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Does the IARU actually represent you?
Foundations of Amateur Radio
<p>
The International Amateur Radio Union or IARU was formed on the 18th of April 1925 in Paris. Today, split into four organisations, consisting of one for each of the three ITU Regions, and the International Secretariat, are said to coordinate their efforts to represent the globe spanning activity of amateur radio.
<p>
Each organisation has its own constitution, which at some point I might compare, but for now I'll focus on the International Secretariat.
<p>
Last updated on the 9th of May, 1989, the constitution has nine pages detailing how the IARU works. After defining its name, it describes its purpose.
<p>
Its objectives shall be the protection, promotion, and advancement of the Amateur and Amateur-Satellite Services within the framework of regulations established by the International Telecommunication Union, and to provide support to Member-Societies in the pursuit of these objectives at the national level, with special reference to the following:
<p>
a) representation of the interests of amateur radio at and between conferences and meetings of international telecommunications organizations;
<p>
b) encouragement of agreements between national amateur radio societies on matters of common interest;
<p>
c) enhancement of amateur radio as a means of technical self-training for young people;
<p>
d) promotion of technical and scientific investigations in the field of radiocommunication;
<p>
e) promotion of amateur radio as a means of providing relief in the event of natural disasters;
<p>
f) encouragement of international goodwill and friendship;
<p>
g) support of Member-Societies in developing amateur radio as a valuable national resource, particularly in developing countries; and
<p>
h) development of amateur radio in those countries not represented by Member-Societies.
<p>
Those are lofty goals and no doubt they have changed over the past century. The objectives as described have been in effect for over 35 years, so we can safely say that they are part and parcel of the current workings of the IARU. This leads me to several questions, mostly uncomfortable ones.
<p>
Over the years I have witnessed the incessant cry for the growth of the hobby in the face of apparent global decline. What I haven't seen is any evidence of the IARU actually doing much towards its own objectives. At this point you might well be chomping at the bit to enlighten me, please do, and you might well be right that the IARU is doing stuff, but the key here is seeing evidence. As I keep saying, if you don't write it down, it didn't happen. You do this for contacts between stations, why should the IARU be any different?
<p>
While the IARU is a recognised United Nations organisation, it's entirely volunteer run and paid for by its members. The International Secretariat is funded by its three regional organisations, which in turn are funded by the member societies in each country like the WIA in Australia, ARRL in the U.S., RSGB in the U.K., JARL in Japan and VERON in the Netherlands; over 160 organisations in all. Those in turn are funded by their members. For a decade or more I contributed to the funding of the IARU through my WIA membership. I note, as an aside, that organisations like the Radio Amateur Society of Australia or RASA and the European Radio Amateurs' Organization or EURAO, which are not recognised by the IARU, do not fund it, unless they're making donations on the side.
<p>
That's important because this hobby, despite its amateur nature, runs on money. If you want to help the IARU, the only way to do so is as a volunteer. That's great if you have money to pay for food and housing, less so if you don't. Similarly, member societies are also, by enlarge, run by volunteers, each doing so in the face of big business and government attempts to increase their spectrum allocation at the expense of amateur radio at every turn.
<p>
This leaves us with an organisation with lofty goals to foster, promote and grow our community, funded and run by volunteers, with in my opinion little to show for its century history.
<p>
Is this the best model? Is this how we make a robust, representative and effective organisation?
<p>
Speaking of representative, in 2018 Don G3BJ, former president of the RSGB and then president of the Region 1 IARU, talked in some detail about how the IARU operates in an enlightening video you can find on YouTube called "RSGB Convention lecture 2018 - So what has the IARU ever done for us?".
<p>
In that lecture Don makes the statement that "the ARRL provides significant additional funding" and "without that [the] IARU would be in very serious problems".
<p>
If you're not a member of the ARRL, what does that mean? How much is significant funding? Is it real money, or is it paper money in the form of office space provided within the ARRL offices in Connecticut? If a member of the IARU International Secretariat is also a member and office bearer of the ARRL, does that buy access? For example in 2021 the ARRL executive committee nominated their past president to become the Secretary of the IARU, which at least according to the ARRL, it "has the right and obligation to".
<p>
I don't know how you feel about that, but it makes me uncomfortable and here in Australia I can't say that I feel represented, even if I was a current and paid up member of the WIA, which I'm not. I think organisations like the member societies and the IARU have a very important role to play in our hobby, but what I don't see is evidence that they are.
<p>
No doubt I'll get emails telling me to step up. I would if I had a functioning money tree in my backyard.
<p>
Transparency is an issue in our community. I left the WIA because I felt that there was no transparency. The ARRL had a wide ranging security breach recently and whilst it has written a great many words on the subject, most of them are, at least in my professional opinion, the opposite of transparent. I have yet to see the operating budget for the WIA, the ARRL or the IARU, despite having paid money into at least two of those.
<p>
So, what of the future of our hobby? What does representation in a modern global community look like and does the structure of our hobby need scrutiny and discussion?
<p>
I'm Onno VK6FLAB
Listen:
Being a Maverick is part of the deal
Foundations of Amateur Radio
<p>
The story goes that the name of our hobby, at least in some parts of the world, ham radio, stems from the notion that we as a community were perceived as being ham-fisted in our ability to operate a Morse key. We apparently claimed that slur and made it our own. I've never actually been able to verify this narrative, but it goes to the heart of what it is to be part of the hobby of amateur radio, as opposed to Professional radio, which is what I once heard someone refer to themselves as.
<p>
This notion that we are playing outside our sandbox, that we're doing something less than real, that we're somehow not whole as a result is absurd, especially in the context of how we are an integral part of how spectrum is allocated around the globe. It's fun to remember that playing outside the box, trialling things, exploring, inventing and learning, is the reason we're here.
<p>
The whole thing is incremental, much like learning to walk, sometimes you fall flat on your face, yet here you are perambulating like a champ. As an aside, did you know that how you get up off the floor is pretty much how you learnt to do it as a toddler, it might not be the most efficient, but it's how you do it. Speaking of falling down, making mistakes on-air is part and parcel of being an amateur. There's no protocol police, nobody to issue a fine if you make a mistake, just dust yourself off and try again.
<p>
The urge to optimise pervades our hobby. We optimise our antennas, our gear, the time and band we choose to communicate on, the modes we use, the places we operate from, even how we participate in contests, all of it is a cycle of optimisation.
<p>
During contests I've regularly attempted to flex my imagination to optimise my activities. For example, the VK Shires contest rewards you for combinations of shires, so, I created a map of all the shires, then looked for places to activate, preferably on or near borders, so I could change shire with minimal effort. There are contests that reward different maidenhead locators, so I set about finding spots where you could activate four at once. By the way, a maidenhead locator is an amateur radio geo-locator which I'll dig into some other time. Contesters regularly use multiple radios to optimise their ability to talk to stations that double their points, so-called multipliers.
<p>
Over the years I've come across many different excuses for getting on-air and making noise. Popular activities like Parks On The Air, or POTA, Summits On The Air or SOTA, and plenty of others are all programs that aim to get you out of your shack, set up your station at a particular location and make contact with anyone and everyone. On occasion you'll hear a station combining activities, doing both a POTA and a SOTA activation because the summit is inside the boundaries of a national park.
<p>
Ian M0TRT took this idea to a whole new level. He wondered if you could qualify for multiple programs simultaneously and if so, how many. Gathering data from Summits, Parks, Islands, Beaches and Bunkers on the Air, together with UK Castle and Lighthouse awards and adding World Wide Flora and Fauna or WWFF, eight programs in all, he set about exploring. For some programs like Castles, Lighthouses and Bunkers you need to be within 1 km of the entity and summits need to be activated within 25 meters altitude from the peak. For other programs, beaches, parks and islands plenty of extra work was needed. Ian's code is available on GitHub, in the "weeaaoa" or "Worked Everything Everywhere All At Once Award" repository.
<p>
If you have time to head out to the beach just east of Devil's Point near Plymouth you'll be able to activate 21 different programs at the same time. The Maidenhead locator is IO70WI06.
<p>
As with any outdoor amateur radio activity, take nothing but pictures, leave nothing but footprints and kill nothing but time. Be mindful of creating obstacles and trip hazards for your fellow humans and be prepared to have a park ranger turn up as soon as you sit down.
<p>
Oh, and if you think that's not in the spirit of amateur radio, you haven't been paying attention.
<p>
I'm Onno VK6FLAB
Listen:
Planning for Contest Success
Foundations of Amateur Radio
<p>
One of my recurring, you might call it, regrets, but probably not quite that strong, is that I often find myself discovering that an amateur radio contest came and went, or worse, I found out on the day, preferably at midnight UTC when many contests start, which happens to be 8 am Saturday morning where I live, right when my weekly radio net for new and returning amateurs, F-troop, begins.
<p>
Often by that time I already have plans for the weekend and now I know I'm missing out on some or other activity that might encourage me to go outside and get fresh air whilst playing radio.
<p>
Don't get me wrong, it's my own responsibility to manage my time, but that doesn't explain what's going on, so I started exploring what might be causing this. I mean, it shouldn't be that hard, there's pretty much a contest on every weekend, so I could sort out my radio and get on-air to make noise at any point of any day. That this doesn't happen can only partially be explained by the state of my shack, which I have yet to get working the way I want, but it doesn't explain everything.
<p>
I'm subscribed to several contest calendars. The most prominent of these is one maintained by Bruce WA7BNM. The contestcalendar.com website is a great place to start. Another is the personal site of prolific contester and contest manager, Alan VK4SN. Both sites offer a calendar feed file that you can subscribe to.
<p>
So, subscribe to the calendar, job done, right?
<p>
Unfortunately not. As it happens, for several years I have in fact subscribed to both those calendars. I even shared these with my partner, which results in a fun exchange at the breakfast table that goes something like this: "Hey, do you need the car on Saturday?" "Why?" "Well there's an amateur contest on."
<p>
So, my partner is often more aware of contests than I am and supposedly I'm the amateur in this household.
<p>
It occurs to me that I need an alert to point at an upcoming contest. Preferably one that I can configure that's specific to me. I don't tend to look that far into the future, I have plenty of stuff that needs to happen today without worrying about next month.
<p>
I started exploring what I might do about this. Be the change you want to see, so I contacted Bruce and asked what views he might hold on the addition of an alarm in the calendar file he publishes. I also asked if there was a way to configure what contests are visible in that file.
<p>
Whilst hunting through his site, I discovered that there's plenty of Australian contests not on the site, so I created a list of contests I know about that I thought should be on the calendar.
<p>
I might point out that Bruce's job isn't easy. Trying to get information out of contest managers can sometimes be like powering a spark-gap transmitter using a pushbike.
<p>
Here's an example of one contest that has an algorithm to determine when the next contest is, I kid you not. There's a Winter, Spring and Summer version of this contest, for Winter, when the June solstice is on a weekday (Monday through Friday), the weekend following shall be the weekend of the event, if not, that weekend shall be the weekend of the event. The Spring and Summer versions are even more involved, counting forwards or backwards four weekends from the December solstice. It helpfully includes a link to the solstice dates for this century, because really, that's how the dates are determined.
<p>
If I'm feeling particularly sparky, I might even make a calculator, since the contest manager for that contest hasn't announced the dates for the next contest, though my previous experiences whilst attempting to calculate moon bounce windows using the Python Astropy package was challenging. I did find PyEphym which has several solstice and equinox functions.
<p>
So, now all I need to do is make my shack work as I want it, bolt a radio back in my car, win lotto and something else, I forget what.
<p>
I'm Onno VK6FLAB
Listen:
About Australian Callsigns
Foundations of Amateur Radio
<p>
Australia has a long relationship with callsigns. Over time the regulator, today the ACMA, the Australian Communications and Media Authority, has seen fit to introduce different types of callsigns and restrictions associated with those callsigns.
<p>
The change that made the most waves most recently was the introduction of the so-called F-call. It's a callsign that looks like mine, VK6FLAB. It has a VK prefix for Australia, the number 6 indicating my state, Western Australia, then the letter F, followed by a suffix of three letters.
<p>
This type of callsign was introduced in 2005. To this day there are plenty of amateurs on-air who don't believe that this is a real callsign, to the point where some refuse to make contact, or worse, make inflammatory statements about getting a real callsign, and that's just the letters, let alone those who think that the callsign denotes a lack of skill or knowledge demanding that the amateur "upgrade" their license to a real one.
<p>
At the time of introduction, the apparent intent was to indicate that the holder was licensed as a Foundation or beginner. In 2020 this was changed, and existing F-call holders were able to apply for a new callsign if they desired. Some did, many did not. Currently there are 1,385 F-calls active and there are 3,748 Foundation class callsigns in the registry.
<p>
After this change, you might think that all callsigns in Australia are now either two or three letter suffixes, as-in VK6AA or VK6AAA. Actually, the F-call continues to exist and there are now also two by one calls, VK6A, intended for contesters.
<p>
A popular idea is that the F-call is for Foundation license class amateurs only. There are currently 10 Standard and 16 Advanced license classed holders with an F-call. There are also two special event callsigns that sport an F-call.
<p>
With the addition of contest callsigns, new prefixes, VJ and VL, were introduced which brought with it the notion that you could use those new prefixes for your callsign. Currently, only contest callsigns are allocated with VJ and VL prefixes.
<p>
An often repeated idea is that we're running out of callsigns. Well, there are 1,434,160 possible callsigns if we count each prefix, each state, single, double, triple and F-calls across all prefixes. As it happens, there are at present 15,859 assigned and 53 pending callsigns.
<p>
If not all, then surely, we're running out of real callsigns. Nope. If we look at the VK prefix alone, less than 10% of available callsigns have been allocated.
<p>
Okay, we've run out of contest callsigns. Nope. There are 1,040 possible contest callsigns and only 188 allocated.
<p>
Another popular notion is that we've run out of two-letter callsigns, that is, the suffix has only two letters. Again, no. There are 3,553 allocated out of 6,760, less than 53% has been assigned.
<p>
Surely, some states appear to have run out of two-letter callsigns. Well, maybe. Theoretically each state has 676 two-letter callsigns but none have all of those allocated. For example, VK3, with 675 allocated two-letter suffixes, is missing VK3NG for no discernible reason. More on the missing ones shortly. It's impossible to use the current register to determine how many amateurs hold more than one two letter callsign.
<p>
Another notion is that you can have a special event callsign as long as it starts with VI. As it happens there are currently special event callsigns registered with VI, VK and AX prefixes. Just over half of them have any online activity to promote the callsign for their event.
<p>
You might think that a callsign can only be "Assigned" or "Available". According to the register a callsign can be "Pending", it can also be "Reserved", more on that in a moment, and it can not be in the list at all, "Missing" if you like. Take for example JNW, it's assigned in VK2, it's available in all other states, except VK3 where it simply doesn't exist. This oddity doesn't restrict itself to VK3. Take XCA, available in all states, except VK4. TLC doesn't exist in VK2. Many more examples to go round.
<p>
And that's not looking at exclusions due to swear words and reserved words like PAN; but SOS is an assigned callsign. Combinations that you think might be unavailable, like QST, are fine, except in VK2 where it doesn't exist.
<p>
It's thought that reservations are only for repeaters. Nope. Suffixes with GG followed by a letter are reserved for the Girl Guides, those that start with S followed by two letters are reserved for Scouts, those starting with WI are for the Wireless Institute of Australia and those with IY are for the International Year of something. Interestingly there is no reference to repeaters or beacons at all in the callsign register since they fall under the old license regime, rather than the new amateur class. And you thought that the system was getting simpler and cheaper to run.
<p>
You might think that every state has the same number of callsigns. Ignoring F-calls, VK5 has the most callsigns available and VK3 the least. No doubt this is due to the callsigns that are "Missing" from the register.
<p>
This likely leaves you with plenty more questions, but next time someone asserts something about callsigns, perhaps it's time to have a think before you spout.
<p>
Note that this information is based on the ACMA callsign register as I found it on the 29th of June 2024. This started as an exploration of just how many different amateur calls were registered.
<p>
At the time there were 3,748 Foundation class, 2,079 Standard class and 9,946 Advanced class callsigns assigned or pending.
<p>
Without knowing how many callsigns each amateur has been assigned, it's impossible to know just how many amateurs those 15,773 callsigns represent. Perhaps it's time for the regulator to start publishing some data on our community, rather than relying on the likes of me to download 1,774 pages of data and two days analysing it.
<p>
I can tell you that I have been assigned two callsigns, one for day-to-day use and one I use for digital modes and contests, given that WSPR doesn't play nice with VK6FLAB and I really have no desire to give up my call.
<p>
Before I go, every VK callsign also has an AX equivalent on three days every year, 26 January, 25 April and 17 May and as I said, you can apply for a special event callsign with an AX prefix.
<p>
I'm Onno VK6FLAB
Listen:
How does the IARU work?
Foundations of Amateur Radio
<p>
Over the past week I've been attempting to work out what the IARU, the International Amateur Radio Union, actually does and how it works. I started looking into this because the IARU is this year celebrating a century since its foundation in 1925. You might think of the IARU as one organisation, but behind the scenes there are actually four, one for each so-called "Region" as well a Global organisation called the International Secretariat, headquartered at the ARRL in Connecticut.
<p>
The Regions have been negotiated by members of the ITU, the International Telecommunications Union. As early as 1927 the ITU documented differences in frequency allocations between Europe and Other Regions. In Cairo in 1938 it defined boundaries for Europe. In Atlantic City in 1947, the ITU defined three Regions, with specific boundaries, essentially, Europe and Africa, the Americas and the rest of the world.
<p>
As a surprise to nobody, this is purely a political decision, especially since radio waves don't get to have a passport and pass border control. The impact of this continues today, generations later. We still have this patchwork of frequency allocations, we still have exclusions, different band-edges and other anachronisms.
<p>
The Regions are further divided into Zones. When you start looking at the ITU zone map in detail it gets weird. For example, Iraq is in Region 1, neighbouring Iran has been specifically excluded from Region 1 and moved to Region 3. In case you're curious, Iran has been represented at the ITU since 1938.
<p>
Antarctica is part of seven of the 90 ITU zones and all three Regions, because of course it is.
<p>
Zone 90, jammed between zones 35, 45, 61, 64, 65 and 76, almost as an afterthought, contains one landmass, Minamitorishima, an island that sticks 9 m above the water, has a 6 km coastline and is generally off-limits to the general public. The nearest land in any direction is over 1,000 km away. It's got an IOTA, Islands On The Air, designation, OC-073 and despite its isolation, has been activated by radio amateurs using JD1 prefix callsigns.
<p>
I live in Australia, ITU zone 58, part of Region 3, together with the two most populous countries on the planet, India and China and the rest of eastern Asia, but not the Former Soviet republics and most, but not all of Oceania, you know, because .. logic. From a population perspective Region 3 is the largest by several orders of magnitude, but you'd never know it if you went looking.
<p>
Why am I telling you all this?
<p>
Well, that's the international stage on which the IARU is representing amateur radio. In 1927 the underlying assumption was that each service, Amateur Radio included, had a global exclusive allocation. The reality was different. Spectrum was in such short supply that individual exceptions were carved out, which as I've said resulted in splitting up the world into regions, starting in 1938 and codified in 1947.
<p>
The IARU in 1925 is a different organisation from what it is today. In 1925 individual amateurs could become members. As soon as enough members from a country joined, they'd be grouped together. When there were enough groups, the IARU became a federation of national associations.
<p>
Over time, the IARU as a single body, evolved into the structure we have today. In 1950 in Paris, the IARU Region 1 organisation was formed. In 1964 in Mexico City, IARU Region 2 was created and in 1968 in Sydney, IARU Region 3 came to exist. You can see their online presence at the various iaru.org websites.
<p>
How it works is no clearer now than it was when I started. What it has achieved is equally unclear. I'm currently trolling through ITU World Radiocommunications Conference documentation going back to 1903 to discover references to Amateur Radio, but it's hard going. At least it's something. The IARU documentation is not nearly as extensive or up to date.
<p>
It appears that many, if not all, of the people working behind the scenes at the various IARU organisations are volunteers. If you feel inclined, there is an ongoing request for assistance, and before you ask, yes, I looked into helping out, but that will have to wait until funds permit.
<p>
If you have insights into the functioning of the IARU, don't be shy, get in touch. cq@vk6flab.com is my address.
<p>
I'm Onno VK6FLAB
Listen:
Problem Solving or How to Access a Radio Remotely?
Foundations of Amateur Radio
<p>
So, I have a confession. I don't know everything. Shocking right?
<p>
Over the past too many months, actually, come to think of it, years, I have not been on-air with my station on HF using FT8 or Olivia, modes that use tools like "WSJT-X" and "fldigi". This has not always been the case. For a time I used a tiny computer running those tools. It had plenty of issues related to its size and capacity. Overwhelmingly it was slow, unsurprising since it was released in 2009. After one particularly frustrating session where I had to recompile WSJT-X on an older 32-bit operating system using an Atom processor, I decided that this was not helping me, and I put it away.
<p>
The idea was to use my main computer that could do all the heavy lifting without cracking a sweat. To make this happen the traditional way, I'd be expected to physically connect the radio to the computer. I'm not a fan of doing that, given the potential damage that RF could do to my computer, not to mention that I have a sit-stand desk on wheels that I move around my office as the mood or the light takes me, if you're interested, I found a mobile lectern that the computer is clamped to. Works great, been using it for years.
<p>
RF aside, moving around the office is not conducive to plugging in a radio that comes with power, coax, audio, control, microphone and expects to have some space around it to actually use it. No problem, I have a RemoteRig, a device that comes in two parts. You connect one unit to the radio, the other to the head, that is, the removable faceplate of the radio, and using a network connection, you can have the head in one place and the radio in another. The two units don't have to be in the same room, let alone the same country.
<p>
I figured that I could replace the second half of the system, the head and its unit, and instead use software on my computer to get the same functionality and be up and running in minutes. That was several years ago. Interestingly, whilst I'm putting this together I did a search for "RemoteRig protocols" and learnt a few things, so perhaps this path isn't quite as dead as I feared. I've reached out to Mikael SM2O and if that comes to anything I'll let you know.
<p>
In the meantime I've been trying to figure out how to operate my radio in software only. I can control the radio if I physically connect a computer like a Raspberry Pi to it and use "rigctld" to interact with it. This gives me access to all the standard CAT, or Computer Assisted Tuning commands. In other words, I can change band, mode, frequency, trigger the transmitter, all the stuff that you need to get on-air to make noise.
<p>
There's only one bit missing, the noise, as-in audio, either coming from the radio, or going to it. I suppose I could trigger a carrier and use it to send Morse, but that doesn't give me receive capability. I've tried using network audio using "pulseaudio" - it never worked right. I've made USB hot-plug scripts that allow you to connect a USB device into a computer and access it across the network on another computer - it mostly works for sound, but reliable is not a word I'd use. I've looked at using the USB sound card in the audio mixer on my desk, but it's subject to all manner of funky restrictions and random audio dropouts. I could use a virtual screen and connect to a Raspberry Pi that's physically connected to the radio, but that's leaving all the hard work on the Pi, rather than the computer that I'm currently using with several orders of magnitude more capability.
<p>
Whilst we're discussing this, one of the reasons I like the idea of a software defined radio like a PlutoSDR, is that the stuff coming out of the radio, and going into it for that matter, is already digital. It takes away a whole lot of complexity, admittedly replacing it with software, but that's where I feel more comfortable.
<p>
Which brings me to you.
<p>
As I said, I don't know everything.
<p>
What are you doing in this space? Are you actually on-air with your contraption, or is it still in the planning stages? Are you sending audio, or digital data across the network? Does your system have the ability to swap out a radio and replace it with something completely different? Do you rely on functions available on the radio, or could it be used for a 1950's valve radio, a twenty year old one, a current model, or any number of software defined radios without issues? Finally, is it Open Source?
<p>
I confess that I'm not holding my breath for an answer, but there is a chance that you're similarly intrigued by this collection of questions that you will poke your head above the fence and make yourself known.
<p>
I'm Onno VK6FLAB
Listen:
Identity in Amateur Radio
Foundations of Amateur Radio
<p>
The recent "incident" at the ARRL in which it disclosed that it was the "victim of a sophisticated network attack by a malicious international cyber group" brings into focus some serious questions around our community in relation to identity and privacy.
<p>
Let's start with your callsign. Right now in Australia you can use the official register to look for VK6FLAB. When you do, you'll discover that it's "Assigned to Foundation". That's it. No mention of who holds it, where it's registered or how to contact the holder, none of that.
<p>
In the case of my callsign, because I haven't surrendered my apparently now legally useless license, you can still search the previous system, the Register of Radiocommunications Licenses and discover that it's held by me, but as soon as it expires, that record will vanish and the relationship between me and my callsign will be lost to the public.
<p>
Also, there are no dates associated with any of this. You cannot use the current or previous system to discover if I held my callsign in November 2010 or not. In case you're wondering, no, I didn't, I was licensed a month later. Right now if you look for VK6EEN on QRZ.com, you'll see that it's linked to CT1EEN, but when was that information last updated? I know for a fact that I became the holder in November 2020. It appears that Sam CT1EEN used it around the turn of the century, about 24 years ago, but precisely when and for how long, is unclear.
<p>
So, from a public disclosure perspective, the links between me and my callsigns are tenuous at best.
<p>
Before I continue, I will point out that this is not unusual. For example, you can see the number plate on my car as I drive down the street, but most people don't have the ability to link it to me.
<p>
Similarly, Ofcom in the United Kingdom released a list of allocated amateur callsigns after a freedom of information request. It's unclear if this information is updated, or if it requires a new request each time. Like Australia, the dataset contains the callsign, the type of license and when the record was last updated. Nothing else.
<p>
In contrast, the United States has a full license search that returns name, address, issue and expiry dates. Japan offers both a search tool and downloads. Interestingly you can see if a callsign was previously licensed and when, but not by whom.
<p>
No doubt each country has their own interpretation in relation to how this is handled and as was the case in Australia, this is ever changing.
<p>
This leaves us with an interesting phenomenon.
<p>
We use callsigns on-air to identify ourselves, but the relationship between the callsign and our identity, let alone when, is not guaranteed for a significant proportion of the amateur community.
<p>
So, how does this relate to the ARRL incident?
<p>
Radio amateurs like to make contacts with each other and collect those contacts like you might collect stickers or postage stamps. For decades we've used QSL cards, essentially a postcard sent from one amateur to another to confirm a contact. When you collect enough cards, you can apply for an award, like the DXCC, showing that you made contact with one hundred different so-called DX entities.
<p>
In the era of computing, some organisations, like the ARRL, came up with the idea of using the internet to exchange these contacts instead of using a postcard. This reduced delays and was presented as a system to make the process more secure by requiring that people electronically sign their contacts, but could only do so after identifying themselves using traditional means, like providing copies of their license, their passport, etc. The ARRL called it Logbook of the World, or LoTW, and it was adopted by the amateur community around the globe.
<p>
While the ARRL continues to state that it only holds public information on its member database, it has made no such assurances about the LoTW system. There is personal and private information that the ARRL has and there is no indication at all what happened to it.
<p>
Other systems such as QRZ, eQSL, Clublog and Hamlog offer similar systems with various levels of authentication and verification. A new player, HQSL, is confusing the issue by offering cryptographically signed QSL cards, boasting that their system is decentralised and not restricted to any single service, but immediately requires that you sign-up with Hamlog to get going.
<p>
So, we have several organisations offering electronic logging, contact confirmation and security which claim to guarantee that this callsign contacted that callsign at a time and date, on a band, using a mode.
<p>
One problem.
<p>
None of this is real.
<p>
For starters, there is no guarantee that the station operating VK6FLAB was me. There is also no record guaranteeing that I'm the holder of VK6FLAB, or any proof that I am who I say I am. There is also no guarantee that the person confirming a contact between VK6FLAB and you is me. So, we're creating a phantom secure system that's attempting to fix the wrong problem.
<p>
In golf, when you start playing for rankings, rather than a round at the 19th hole, the process used to verify your score is dependent on peer review. You cannot mark your own score-card, someone else does.
<p>
In amateur radio we've built this electronic house of cards to track whom we've talked to and when, but it's a mirage when looked at closely.
<p>
While a DXCC award is worth nothing more than a personal achievement, we cannot go on pretending that identity verification services like LoTW are real, nor can we continue to accept that organisations like the ARRL should demand and store valuable identity information.
<p>
I'm Onno VK6FLAB
Listen:
Long Wave Radio
Foundations of Amateur Radio
<p>
If you've heard the phrase "shortwave listeners", you might have wondered what on earth that was all about.
<p>
It relates to the length of a radio wave used to transmit information. The length of a radio wave is tied to its frequency. The longer the wave, the lower the frequency.
<p>
When radio amateurs talk about bands, like for example the 40m band, we're talking about a range of frequencies where the wavelength is around 40m. From a frequency perspective, this is around 7 MHz. The 160m band, at about 1.8 MHz, or 1,800 kHz is considered the beginning of the short wave bands.
<p>
This implies that there are longer waves as well. If you've ever seen or owned a mid 1980's transistor radio, you'll have seen the notation MW, which stands for Medium Wave, today it's called the AM band. Older radios might have the notation LW, or Long Wave.
<p>
The medium wave band is a broadcast radio band that runs between about 500 and 1,700 kHz. The wave length is between 600 m and 170 m.
<p>
When radio was still in its infancy, there was also a popular long wave band, with wavelengths between 800 m and 2,000 m, or 150 to 375 kHz.
<p>
Today much of that has gone by the wayside. With the advent of digital radio, in Australia it's called DAB+, Digital Audio Broadcasting, the whole idea of "wave" has pretty much vanished.
<p>
Some countries like Japan and the United States are in the process of discussing the phasing out of the AM broadcast band. Much of that appears to be driven by car manufacturers who claim that the AM band is no longer useful or used, but forget to tell anyone that they really want to stop having to put AM radios in their cars because it's difficult to isolate the electrical noise from their modern contraptions in order to make it possible to actually listen to that band.
<p>
If you ask me, it's a good incentive to make electronics RF quiet, something which is increasingly important in our wirelessly connected world.
<p>
This might lead you to believe that all activity on air is moving to higher and higher frequencies, but that's not the case. The properties that made long wave and medium wave radio possible in the early 1900's are still valid today. For example, there are WSPR or Weak Signal Propagation Reporter beacons on the 2200m band, or at 136 kHz.
<p>
Whilst your RTL-SDR dongle might not quite get down that low, most of them start at 500 kHz, you don't need to spend big to start playing. My Yeasu FT-857d is capable of tuning to 100 kHz, plenty of space to start listening to the 2200m band, even if I cannot physically, or legally, transmit there.
<p>
If you want to build your own receiver, you can check out the weaksignals.com website by Alberto I2PHD where you'll find a project to build a receiver capable of 8 kHz to 900 kHz using a $50 circuit board.
<p>
If that's not enough, there's radio experimentation happening at even lower frequencies. Dedicated to listening to anything below 22 kHz, including natural RF, with a wavelength greater than 13 km, Renato IK1QFK runs the website vlf.it where you'll find receivers and antennas to build.
<p>
Given that most sound cards operate up to around 192 kHz, you can start by connecting an antenna to the microphone port of your sound card and use it to receive VLF or Very Low Frequencies. On your Linux computer you can use "Quisk" to tune.
<p>
There are VLF transmitters on air. For example, SAQ, the Grimeton Radio Station in Sweden opened on the 1st of December 1924. Capable of 200 kW, today it uses about 80 kW and transmits twice a year on 17.2 kHz.
<p>
While we search for higher and higher frequencies, there is still plenty of fun to be had at the other end of the radio spectrum. Consider for example that VLF or Very Low Frequency radio waves, between 3 and 30 kHz can penetrate seawater.
<p>
I'll leave you to explore.
<p>
I'm Onno VK6FLAB
Listen:
The ARRL incident of May 2024
Foundations of Amateur Radio
<p>
Today I want to talk about something that might feel only tangentially related to our hobby, but it likely affects you.
<p>
Recently the ARRL announced that it was "in the process of responding to a serious incident involving access to our network and headquarters-based systems". A day later it sought to assure the community that the "ARRL does not store credit card information" and they "do not collect social security numbers" and went on to say that their "member database only contains publicly available information". Five days after that it's "continuing to address a serious incident involving access to our network and systems" and that "Several services, such as Logbook of The World(R) and the ARRL Learning Center, are affected.", but "LoTW data is secure". Over a third of the latest announcement, more than a week ago, was to assure the community that the July QST magazine is on track but might be delayed for print subscribers.
<p>
Regardless of how this situation evolves, it's unwelcome news and much wider reaching than the ARRL.
<p>
LoTW, or Logbook of The World, is used globally by the amateur community to verify contacts between stations. The IARU, the International Amateur Radio Union, is headquartered at the ARRL office.
<p>
I've been told that I should have empathy and consider that the ARRL is only a small organisation that may not have the best of the best in technology staff due to budget constraints and finally, that LoTW being down for a few days is not going to kill anyone.
<p>
All those things might well be true and mistakes can and do happen.
<p>
The ARRL has been in existence for well over a century, bills itself as the answer to "When All Else Fails" and has even registered this as a trademark, but hasn't actually said anything useful about an incident that appears to have occurred on the 14th of May, now over two weeks ago. By the way, that date is based on the UptimeRobot service showing less than 100% up-time on that day, the ARRL hasn't told us when this all occurred, it didn't even acknowledge that anything was wrong until two days later.
<p>
This raises plenty of uncomfortable questions.
<p>
What information did you share with the ARRL when you activated your LoTW account? For me it was over a decade ago. I jumped through the hoops required and managed to create a certificate. What information I shared at the time I have no idea about. As I've said before, I do know that security was more extreme than required by my bank, even today, and the level of identification required was in my opinion disproportionate to the information being processed by the service, lists of amateur stations contacting each-other.
<p>
Something to take into account, on the 30th of October 2013, Norm W3IZ wrote in an email to me: "Data is never removed from LoTW." - I have no idea how much or which specific information that refers to.
<p>
If you used the ARRL Learning Center, what information did you share? If you're a member of the ARRL, or you purchased something from their online store, what data was required and stored? Is the data at the IARU affected? What infrastructure, other than the office, do they share?
<p>
While I've been talking about the ARRL, this same issue exists with all the other amateur services you use. QRZ.com, eQSL.cc, eham.net, clublog.org, your local regulator, your amateur club, your social media accounts, all of it.
<p>
What information have you shared?
<p>
Do you have an internet birthday, address and middle name?
<p>
Recently I received a meme. It shows two individuals talking about life, the universe and everything. They discuss their favourite books, the first movie they ever watched, the name of their pets, what car they learnt to drive in, their interests and other things you talk about when you meet someone new and interesting. The last image of the meme shows the heading: "Security Questions Answered, Welcome Amanda."
<p>
So, my question is this: What's your favourite colour and your mother's maiden name?
<p>
Seriously, next time you access a service online, have a look at what data that service has. When you sign up, consider the requirements for the service and how much information that's worth. Do you really need to send your birthday, your gender and your physical address with a copy of your passport or another government approved identity document? If you're being asked for the name of your first pet, consider answering something unique. In my case, I generate a random string of characters to use as an answer for each security question.
<p>
The ARRL "incident" is the tip of the iceberg. This problem is't going away, it's only going to get bigger and happen more often.
<p>
Final observation. With the potential of a global shopping list for thieves coming out of the database at the ARRL, will you be sharing your station address next time and if you're subject to the GDPR, the General Data Protection Regulation, perhaps it's time to ask your online service providers just exactly what they're doing to protect your information, and that includes the ARRL.
<p>
I have sent two emails to the ARRL in relation to these questions, but have yet to receive an acknowledgement, let alone answers.
<p>
By the time this reaches you, perhaps the ARRL has answers to my questions and more.
<p>
I'm Onno VK6FLAB
Listen:
The origin of our amateur bands
Foundations of Amateur Radio
<p>
The origin of our amateur bands
<p>
It's hard to imagine today, but there was a time when there was no such thing as either the 80m or the 20m amateur band, let alone 2m or 70cm.
<p>
Picture this. It's the roaring 20's, the 1920's that is. Among a Jazz Age burst of economic prosperity, modern technology, such as automobiles, moving pictures, social and cultural dynamism, the peak of Art Deco, we're also in the middle of a radio boom where the world is going crazy buying radios as fast as they can be constructed, there are hundreds of licensed broadcasters, the bands are getting crowded, radio amateurs have been banned from the lucrative radio spectrum above 200 meters, and can only play in the "useless short waves" using frequencies greater than 1,500 kHz. And play they did.
<p>
On the 2nd May 1925 amateurs proved they could communicate with any part of the world at any time of the day or night when Ernest J. Simmonds G2OD and Charles Maclurcan A2CM made a daylight contact between Meadowlea, Gerrards Cross, Buckinghamshire, England, and Strathfield, Sydney, New South Wales, Australia on what we now call the 20m band. This contact occurred not once, but regularly, for several days, using 100 Watts.
<p>
To give you a sense of just how big news of this feat was, on the second scheduled contact the Prime Minister of Australia, Stanley Bruce, sent a message to England's Prime Minister, Stanley Baldwin: "On occasion of this achievement Australia sends greetings."
<p>
If you recall, the IARU, the International Amateur Radio Union, was a fortnight old at this point. Less than a year later contact was made using voice.
<p>
Between the banning of radio amateurs from frequencies below 1,500 kHz at the London International Radiotelegraph Conference in 1912 and the Washington International Radiotelegraph Conference in 1927 the world had irrevocably changed. In 1912 the discussion was almost all about ship to shore communication. By 1927, the world had tube transmitters, amplitude voice modulation, higher frequencies and what the 1993 IARU President, Richard Baldwin, W1RU calls, "literally an explosion in the use of the radio-frequency spectrum".
<p>
In 1927 individual countries were beginning to control the use of spectrum, but there was no universal coordination, no international radio regulation and as we all know, radio waves don't stop at the border.
<p>
Richard W1RU, writing in 1993 says: "In retrospect, the Washington conference of 1927 was a remarkable effort. It created the framework of international radio regulation that exists even today. It had to recognize and provide for a multitude of radio services, including the Amateur Service. It was at this conference that amateur radio was for the first time internationally recognized and defined. Bands of harmonically related frequencies were allocated to the various radio services, including the Amateur Service."
<p>
While the IARU was two years old, it really hadn't represented amateur radio on the international stage, until now.
<p>
The 1927 conference defined an "amateur" as a "duly authorised person interested in radio electric practice with a purely personal aim and without pecuniary interest."
<p>
The harmonically related frequencies that were allocated to the Amateur Service are recognisable today. I'll use current band names to give you some context.
<p>
1,715 kHz to 2 MHz, or 160m, 3.5 to 4 MHz, or 80m, 7 to 7.3 MHz or 40m, 14 to 14.4 MHz or 20m, 28 to 30 MHz or 10m, and 56 to 60 MHz or 6m.
<p>
Of those, the 20m and 80m bands were exclusive to amateurs. The 10m and 6m bands were shared with experimenters and the 160m and 80m bands were shared with fixed and mobile services. You'll notice the absence of bands we use today, the 2m and 70cm bands, 15m and the so-called WARC bands to name a few.
<p>
The final ratified document goes into great detail about the requirements, the restrictions, how to deal with interference, how to allocate frequencies and numerous other provisions, many of which will look familiar, almost a hundred years later, if you've ever looked at the rules and regulations under which you operate as a licensed amateur today.
<p>
There were various radio amateurs at the 1927 conference, but as Richard W1RU puts it: "much of the credit for the success of amateur radio at that conference has to go to two representatives of ARRL -- Hiram Percy Maxim, president of ARRL; and Kenneth B. Warner, Secretary and General Manager of ARRL."
<p>
While Richard points to their roles in the ARRL, you might recall that Hiram was elected international president of the IARU and Kenneth its international secretary-treasurer.
<p>
Whichever way you look at it, whichever organisation you credit, today we have amateur bands thanks to those efforts made nearly a century ago.
<p>
I'm Onno VK6FLAB
Listen:
On the nature of Inspiration ..
Foundations of Amateur Radio
<p>
Over the years you've heard me utter the phrase: "Get on air and make some noise!". It's not an idle thought. The intent behind it is to start, to do something, anything, and find yourself a place within the hobby of amateur radio and the community surrounding it.
<p>
Since starting my weekly contribution to this community, thirteen years ago, almost to the day, I promise, this wasn't planned, you'll see why in a moment, I've been working my way through the things that take my fancy, things that are of interest to me, and hopefully you. From time-to-time I don't know where the next words are going to come from. Today they came to me five minutes ago when a good friend, Colin, VK6ETE, asked me what inspires me, after I revealed to him that I didn't know what I was going to talk about.
<p>
That's all it took to get me rolling.
<p>
There are times when getting to that point takes weeks, I do research, figure out how something works, explore how it might have been tackled before, if at all, and only then I might start putting my thoughts together, often I'll have multiple stabs at it and if I'm lucky, sometimes, something emerges that I'm astonished by. Today is much simpler than all that, since the only research required is to remember the people I've interacted with.
<p>
Last week I met an amateur, Jess M7WOM, who was in town. Until last week, we'd never met and interacted only online. We discovered that we have a great many things in common. A joy for curiosity, exploration, technology, computers and a shared belief that we can figure out how to make things work. That interaction, over the course of a day, continues to fuel my imagination and provides encouragement to try new things.
<p>
The same is true for a friend, Eric VK6BJW, who asked what they should do with the hobby after having been away for a long time with family, children, commitments and work. Just asking a few simple questions got the juices going and provided inspiration to start playing again.
<p>
Another amateur was bored and claimed to have run out of things to do. A few of us started asking questions about their exposure to the hobby. Had they tried a digital mode, had they built an antenna, had they tried to activate a park, or as I have said in the past, any of the other 1,000 hobbies that are embedded within the umbrella that we call amateur radio.
<p>
Right now I'm in the midst of working through, actually truth be told, I'm starting, Okay, actually, I've yet to start, reading the online book published at PySDR.org. Prompted by a discussion with Jess last week, I started exploring a known gap in my knowledge. I likened it to having a lamp-post in front of my face, I can see to either side, but in-between is this post, obscuring an essential piece of knowledge, how one side is connected to the other. In my case, on one side, I can see the antenna, how it connects to an ADC, or an Analogue to Digital Converter. On the other, I can also see how you have a series of bytes coming into your program that you can compare against what you're looking for, but the two are not quite connected, obscured by that .. post. I know there's a Fourier Transform in there, but I don't yet grok how it's connected.
<p>
Recently I discussed using an RDS, or Radio Data Systems decoder, called 'redsea', connected to 'rtl_fm', in turn connected to an RTL-SDR dongle, that is, you connect an antenna to a cheap Digital TV decoder, tune to an FM broadcast station and use some software to decode a digital signal. It turns out that the PySDR book serendipitously uses this signal path as an end-to-end tutorial, complete with all the code and example files to make this happen. I actually read the chapter, but it's assuming some knowledge that I don't yet have, so I'm going to start on page one .. again.
<p>
So, what has this got to do with Inspiration, you ask. Well, everything and nothing. Inspiration doesn't occur in a vacuum. It needs input. You cannot see light without it hitting something, radio waves don't exist and cannot be detected until it hits an antenna, the same is true for inspiration. It needs to hit something. You need to react, it needs to connect.
<p>
That is why I keep telling you to get on air and make some noise.
<p>
I'm Onno VK6FLAB
Listen:
Automatic FM DX decoding
Foundations of Amateur Radio
<p>
Much is made in our hobby about working DX, that is sending and receiving distant radio signals. How distant is up for debate. Depending on where you are, DX might be outside the continent, outside the country, or in my case you could easily say, anything outside of my state, since the nearest border is about 1,240 km away from here. For giggles, the distance between Albany in the South West and Wyndham in the North East of the state is 2,400 km and that's via radio wave. By car it's 3,570 km. To be clear, we're still inside VK6.
<p>
All that to say, DX is in the ear of the beholder.
<p>
If that's not enough, there's a group of amateurs who are of the strident opinion that for DX to count it must be a two-way contact. That is, both stations need to hear each other and as such, those amateurs believe that a mode like WSPR, the Weak Signal Propagation Reporter can't possibly be considered DX, even if you can discover that your station was heard on the other side of the planet.
<p>
I'm going to skip right over those who tell anyone who will listen that FT8 isn't real radio because it's just computers talking to each other.
<p>
This to give you some context when I introduce the next idea, namely FM Broadcast DX. I'm acutely aware that this isn't amateur radio, there's no two-way communication, it's probably not DX and besides, it's computers. That out of the way, let me tell you about something I discovered.
<p>
Many, but not all, FM broadcasters transmit multiple signals when you tune to their station. One of those is a signal called RDS, or Radio Data Systems. It's used to show you the name of the station, sometimes what song is playing, what style of station it is and other information like road traffic alerts and emergencies. You can decode this using an RDS decoder.
<p>
Recently I was browsing YouTube. I came across a video on the Broken Signal channel that digs into the world of FM-scanning to log any RDS information for the purpose of finding DX stations. The video goes into great detail on how to set this up with Windows, by copying files into various places, updating XML files, configuring sample rates, connecting virtual audio cables, running several tools simultaneously and it goes on to demonstrate how this all hangs together.
<p>
While I was impressed with the idea, the implementation didn't speak to me, since I wince at the notion of copying random files into an application installation directory and besides I'm a Linux user.
<p>
So, I went hunting.
<p>
Turns out that there is an RDS decoder for Linux, called "redsea", written by Oona OH2EIQ. It's on GitHub. Compiling it is pretty straightforward, follow the instructions and it should work as advertised. You'll also need to have "rtl-sdr" installed so you can run a tool called "rtl_fm". Again Oona's instructions should help you out. I will add that I'm assuming that you have a so-called RTL-SDR dongle, it's a cheap USB device that can be coerced into pretending to be a software defined receiver with about 2.2 MHz of bandwidth.
<p>
Based on the example shown, I immediately tuned to a local station and RDS information started filling my screen. To let you know how simple this is, you run the "rtl_fm" tool and send its output to "redsea" which decodes the information and displays it on the screen. That's it. No more moving parts, no XML files, no shenanigans with virtual audio cables and the like.
<p>
Stage one complete, on to stage two, scanning.
<p>
The "rtl_fm" tool has the capability to scan a range of frequencies. I tried this, but didn't really get anywhere, since for the scanner to work you need to set the squelch in order to switch between frequencies, but if you're aiming for a weak signal, it will never be heard if your local FM broadcasters are belting away 24 hours a day.
<p>
So, instead I'm scanning each frequency between 87 MHz and 109 MHz, every 10 kHz, for 10 seconds, to see if there's any RDS data to be heard. I send that to a file and when I feel the urge, I can go check to see what I've heard.
<p>
I haven't yet put this up on GitHub because I'm considering making it a contribution to the "redsea" project instead of a project of my own.
<p>
Now, at this point you might wonder what all the fuss is about. Well, the same method could be used to decode your local amateur repeater idents, or the NCDXF beacons, or any other kind of interesting information. I saw one user link "rtl_fm" to "multimon-ng", a tool I've spoken about before.
<p>
You should also check out Oona's website, windytan.com, there's a whole range of signal processing stories to be found, including dealing with flutter distortion on Steamboat Willie and a very cool spiral spectrogram.
<p>
I'll leave you with one question. Why haven't you installed Linux yet?
<p>
I'm Onno VK6FLAB
Listen:
A place for everything and everything in its place..
Foundations of Amateur Radio
<p>
Some life lessons require additional reinforcement from time to time. This week I was strongly encouraged to remember a lesson that can be summarised as: "A place for everything and everything in its place." It was first uttered like that to me a quarter of a century ago by a client who used it frequently around their staff.
<p>
It means that all the stuff that fills up the space around you, in this case, physical stuff, needs to have a specific home and if you're not actively using it, that is where it should be. This is useful in a context where you have lots of little things that you need from time-to-time, or if you have several people dependent on the availability of a single thing, like say the labelling machine used to tag equipment.
<p>
The other day an incident involving a tiny tablet that went flying across the kitchen bench, bounced over the edge and vanished, not helped by the fact that taking the tablet was time sensitive and the fact that the vacuum cleaner was right there - no the tablet was not inside, I checked. I walked around the bench to the other side and started rolling on the ground with the aid of the torch on my phone. Ten minutes in, still nothing. I remembered that my go-bag has a torch, so I went to get it from its place.
<p>
One problem, it wasn't there. I turned the bag upside down and went through it. Nope, no torch. That's two things that vanished. Neither has resurfaced at this point. I went to the chemist to get another tablet and took it 40 minutes late.
<p>
The torch however was not so easy to resolve.
<p>
My, what I call go-bag, has a bunch of life affirming essentials. It started pretty soon after becoming a radio amateur. It has two jumpers, long-leg underwear, an under shirt, a towel and a microfibre cloth, leather gloves, mosquito net, medication, band-aids, toilet paper, soap and some empty bags. It also has a torch, well, not right now it doesn't.
<p>
After failing on my mission to locate the torch, I started stuffing the contents of my go-bag, straight back into its bag, only to realise that I wasn't helping future me. I stopped, pulled everything back out and started folding everything neatly. Then I repacked the bag.
<p>
I've put in a stand-by torch, in Dutch they're called a "knijpkat", or a mechanically operated torch. You squeeze it in your hand and in doing so you move a dynamo that charges either a battery or a capacitor. It's called a "pinch cat" because it sounds a little like that. The light is fine for getting around in the dark, but you wouldn't mistake it for a super bright, eyeball burning, LED torch.
<p>
In case you're wondering why I'm going into such detail about this, it's because you never know when you need something. It might be urgent, or it might not be. Having your stuff organised in such a way that you can find it, can sometimes be the difference between life and death.
<p>
Now I get it. Not everyone works like this. I have for decades had a system on my desk where I know where all the bits of paper are and it's not helpful if someone cleans it up, because at that point I have no reference to anything and I will have to go through the whole box of things to find what I need.
<p>
When my partner and I travelled around Australia in an Iveco Daily stuffed to the gunnels with electronics equipment, clothes, food, camping gear, a two metre satellite dish and plenty of other things, I had a system that involved four filing cabinets bolted into the van, combined with a dozen or more crates, metal hooks, straps and a safe. I was forever putting things away in the exact same place, each time.
<p>
It's not a process that comes naturally to everyone and so we settled on a process where I would pack the van so I could lay my hands on anything within seconds, from the socket set to the satellite signal finder, from a clean pair of shorts to a raincoat, from a fuel funnel to a water funnel. Pro-tip, don't mix the two. Tools aside, of course this system also applies to the first aid kit and the fire extinguisher, the fire blanket, band-aids and medication, and in this case a torch.
<p>
You might ask how this could apply to amateur radio. Go-bag aside, looking around my radio shack, it has lots of little things, like adaptors, measuring gadgets, chargers, fly leads, microphone clips, coax switches and plenty of other stuff.
<p>
If everything in your shack is in use, this isn't an issue, but if you're like me and don't have your NanoVNA, and all the SMA to something adaptors, or plenty of other things lying around for that "just in case" time, then having a place for everything and everything in its place is a very productive way to keep things organised so you don't spend half your life looking for things.
<p>
Similarly, if you know where your portable shack is, your battery charger, an emergency antenna, or some other essential item, you'll discover that when it comes down to the pointy end of a situation, this might make a difference.
<p>
So, how do you keep your life, and shack, organised and what other processes and methods have you tried?
<p>
I'm Onno VK6FLAB
Listen:
The origins of the International Amateur Radio Union
Foundations of Amateur Radio
<p>
In the early 1920's long distance communication using radio was a growing interest. At the time it was thought that communication that we take for granted today, over long-distance HF, was limited to long wave or extremely low frequencies, the lower the better. With that restriction came massive antennas and high power transmitters, available only to commercial and government stations.
<p>
Then radio amateurs let the cat out of the bag by discovering that so-called "short wave" radio could be heard all across the globe. As an aside, today, "short wave" seems quaint, because we've discovered that even shorter waves can be used to communicate, right down to nanometre communication as shown by NASA in its XCOM technology demonstration on the 12th of May, 2019. On a daily basis we use 120 mm and 60 mm waves when we use 2.4 and 5 GHz Wi-Fi for example.
<p>
As a result of the discovery of short wave radio, a gold-rush emerged. There was a hunger in the community for radio, businesses and communities adopted the new medium, there were radio courses being taught in Universities, church services and other forms of entertainment started filling the airwaves. Comedy, talk shows, music, concerts, serials and dramas spread across the electromagnetic spectrum and radio amateurs who had discovered the phenomenon were running the risk of being pushed aside by commercial interests willing to pay for access.
<p>
As I've said before, in many countries at the time, amateur radio was actively discouraged, sometimes it was even illegal.
<p>
Before we continue, I should quote some statements made about radio before the gold-rush which at the time was seen as "Telegraphy Without Wires".
<p>
In 1865 a Boston Post editorial proclaimed: "Well-informed people know it is impossible to transmit the voice over wires and that were it possible to do so, the thing would be of no practical value."
<p>
Lord Kelvin, President of the Royal Society, said: "Radio has no future." and went on to say: "Wireless is all very well but I'd rather send a message by a boy on a pony", he also said: "Heavier-than-air machines are impossible." and "X-Rays will prove to be a hoax."
<p>
Not all statements aged as badly. The New York Times said in 1899: "All the nations of the earth would be put upon terms of intimacy and men would be stunned by the tremendous volume of news and information that would ceaselessly pour in upon them."
<p>
Back to the IARU. Before a business trip to Europe, the board of directors of the ARRL asked their President, Hiram Percy Maxim, to encourage international amateur relations, which on 12 March 1924 resulted in a dinner given, at the Hotel Lutetia in Paris according to Hiram, a "certain dining room" by "the most distinguished radio men of Europe."
<p>
Hiram goes on to say that: "This A.R.R.L. President has sat in at a good many very impressive radio meetings in the past, ranging from Maine to California, but he has never sat in at a meeting where there was quite as much thrill as at this meeting in Paris where the amateurs of nine different countries sat down together."
<p>
The countries were, France, Great Britain, Belgium, Switzerland, Italy, Spain, Luxembourg, Canada and the United States. Hiram remarks that "Denmark was represented by a letter in which regret was expressed at the inability to have a representative present and asked that the amateurs of Denmark be counted in." You should dig up a copy of the May 1924 edition of QST to get a sense of occasion where the ARRL president compares the thrill of the "hamfest" to the atmosphere during that dinner and pities those who have never experienced it.
<p>
During the meeting it was decided to form an organisation which was going to be called the International Amateur Radio Union. A temporary committee was formed that appointed Hiram Maxim as the chair and Dr. Pierre Corret as secretary to take charge of the details to create a permanent organisation. The final decision was to call for a general Amateur Congress on the Easter Holiday of 1925 where the IARU would be formalised.
<p>
On the 14th of April, 1925, 250 radio amateurs from 23 countries met in Paris and over the next four days the details of the new Union were hammered out. Among those details were that the organisation was chiefly for "the coordination and fostering of international two-way amateur communication, that it should be an organisation by individual memberships until strong national societies had been formed in the principal nations and a federation would be feasible, and that its headquarters would be located in the USA."
<p>
The constitution was written over a day and night session and by the morning of the 17th of April, every delegate had a copy and then the hard work began, approving the constitution, section by section, by the entire Congress. On the morning of the 18th, elections were held and Hiram U1AW was elected international president, Gerald G2NM, international vice-president, Jean F8GO and Frank Z4AA councillors-at-large and Kenneth U1BHW international secretary-treasurer.
<p>
With the election complete, the IARU was officially in business.
<p>
The new constitution was published in English, French and Esperanto. Why Esperanto, you ask? In the middle of 1924, the ARRL adopted Esperanto as its official auxiliary language. According to Clinton B. DeSoto, W1CBD, author of a fabulous book "Two Hundred Meters And Down - The Story of Amateur Radio", that might have been the highest official recognition that language ever received.
<p>
Credit to Clinton for much of the time line and wording I've shared here. I'll leave you with one final quote from his book.
<p>
Clinton W1CBD writes: "One day amateur television is bound to come, however remote though that day may be. It is, indubitably, inevitable that one day amateurs will be able to see each other, as well as talk with each other; and when that day comes the development of amateur radio as a social institution will have taken another great step forward - at least according to present standards. But by then the standards will have changed, and amateurs will have something more to work toward, and the ultimate will still not have arrived. There are always new goals, new horizons. May it fall to amateur radio to march many steps toward the goal of complete knowledge ere its footprints are lost in the sands of time!"
<p>
I'm Onno VK6FLAB
Listen:
Weaving radio into your life.
Foundations of Amateur Radio
<p>
A great deal of energy is expended on the notion of operating portable. I've talked about this plenty of times. Issues like power, antennas, suitable radios, logging, transport and time of day all come to mind. Some activities are framed specifically as portable operations. Things like Summits On The Air, or SOTA, Parks On The Air, or POTA, World Wide Flora and Fauna, or WWFF. There's field days, portable contests and specific activities like the 2014 activation of FT5ZM on Amsterdam Island and the 2016 activation of VK0EK on Heard Island. I mention those last two specifically since I had the distinct pleasure of meeting those teams and had the opportunity to interview each amateur whilst enjoying a typical Aussie BBQ. I'll point out that no shrimps were thrown anywhere. You can find those interviews with FT5ZM and VK0EK on my website at vk6flab.com.
<p>
Each of these activities are framed in the context of the activity, as-in, you climb a mountain with a radio and then you make noise.
<p>
That's not the only way to go portable. One of my friends checks in to the weekly F-troop as a portable station most weeks. Glynn VK6PAW gets in his car, drives to some random location and participates from wherever he happens to be at the time. In doing so, the radio part of it, is the add-on between leaving home and arriving at a destination for a cup of coffee.
<p>
Charles NK8O works all over the United States. When he checks into F-troop, he's rarely in the same place two weeks in a row. In between work and sleep you'll find him activating a nearby park. He's been doing this for quite some time. While this is a POTA activity, he finds parks that fit into his life, rather than point at a park and make a specific trip there to activate it.
<p>
Before I continue, I'd like to mention that I'm not dismissing making a specific trip. Far from it. The point I'm making is that making any such trip is extra work. It's an added activity in your life. Whilst entirely enjoyable, there's plenty of times where that's just not possible.
<p>
Instead I'd like to look at this from the other side.
<p>
Both Glynn and Charles have a radio with them. Perhaps not all the time, but often enough that they can activate their station when they happen to be in a suitable location.
<p>
I've similarly put a radio into my luggage when going on a holiday. It might transpire that it stays there, or it might be that I happen to find a picnic table at the side of a water reservoir that happens to be in the shade and just begging to try a radio at.
<p>
In other words, if you have a radio handy, you can handily use it when the opportunity comes to pass.
<p>
So, what do you bring with you? If you're like Charles, you'll have a QRP radio, a Morse key, a battery and a wire antenna. Glynn has a vertical that lives in his car and the radio is bolted in.
<p>
For a while I had my radio permanently mounted in my car and I suspect that will return there in the not too distant future. It was removed for a service that involved the transmission being replaced after it failed after only a 140,000 km on the clock. Thankfully a fellow amateur had a spare car we could use, but I wasn't game to drill holes for an antenna and I'm pretty sure they were pretty happy about that.
<p>
The more I look at the activities that others report on, the more I have come to realise that the people who get on-air the most are the ones who have found a way to weave radio into their day-to-day life, rather than rely on specific amateur radio activities and plans.
<p>
I confess that I miss sitting by a local lake making noise or finding a random car park with shade that is just begging for someone, anyone, to turn on a radio and have a go.
<p>
So, how do you approach radio in your life, and how might you find ways to incorporate it into the gaps?
<p>
I'm Onno VK6FLAB
Listen:
RF is all around us ... starting your own station frequency survey
Foundations of Amateur Radio
<p>
As a self-proclaimed radio nerd I'm aware of the various amateur bands. Depending on your license, your familiarity will likely vary. I've never been on 6m for example, but I have a good working relationship with the 10m band.
<p>
Amateur bands aside, there's plenty of other activity across the radio spectrum. It occurred to me that I've never actually stopped to take note of what specifically I can hear from my own station. Think of it as a station frequency survey.
<p>
Obvious sources are AM and FM radio broadcasters. Then there's the aviation frequencies, the local control tower, arrival and departure frequencies as well as Perth airport ground on occasion. There's the ATIS, the Automatic Terminal Information Service. There was a time when I could hear various aviation non-directional beacons, or NDBs, that are near me, but many of them were switched off in 2016. I haven't yet found a current list of which of the 213 remaining navigation aids that form part of the Backup Navigation Network across Australia are still on the air.
<p>
As it happens, there's currently some horrendous noise on HF with several new potential sources that I have not yet identified, a pool pump, a bank of solar panels, plasma TV, you name it.
<p>
Staying with aviation, I've briefly played with Automatic Dependent Surveillance-Broadcast, better known as ADS-B, or ADSB, on 1090 MHz. If you have a PlutoSDR, I updated the dump1090 program to use Open Street Map several years ago. You can find it on my VK6FLAB GitHub page. If you want to see some very interesting visualisations for ADSB, have a look at the adsb.exposed website.
<p>
Further up the frequencies are things like 2.4 and 5 GHz Wi-Fi. In a previous life, before I was an amateur, I played with Ku-band satellite frequencies in the range between 12 to 18 GHz, specifically DVB-S, or Digital Video Broadcasting - Satellite.
<p>
While that's an impressive list of things, it leaves an awful lot of unexplored territory. For example, the local trains and public transit authority, the fire and emergency services, the volunteer bush fire brigades, water bombers and the like.
<p>
I've not even looked at local digital services like DVB-T, that's the terrestrial standard, or the local radio version, DAB+, or Digital Audio Broadcasting.
<p>
Then there's pagers, and countless marine services and channels, the ubiquitous CB frequencies and a couple of pirate ones, and global services like GPS, weather satellite and other Earth monitoring services.
<p>
Note that I'm specifically highlighting things that I can hear at my station, or more precisely, should be able to hear. I'm in the process of figuring out which particular tools I need to actually have a stab at hearing and decoding things like weather satellite.
<p>
I wouldn't be me if I didn't try this with my hands tied behind my back. I'm limiting myself to things I can hear using the antennas that I already have. I don't, well not at this stage, want to start building and installing more antennas, probably because in the not too distant future I plan to finally erect a replacement HF antenna, but that's a story for another day.
<p>
As for now, I'm plotting noise levels using a tool called rtl_power. I'm working on figuring out what extra noise has joined my environment. I'm also starting to make a concerted effort to document specifically what I've actually heard. Not so much a continuous log, more of a one-way log if you like, some might call it a shortwave listener log.
<p>
What RF sources have you heard in your shack and how many of them did you document?
<p>
I'm Onno VK6FLAB
Listen:
It's all just text!
Foundations of Amateur Radio
<p>
The other day I had an interesting exchange with a contest manager and it's not the first time I've had this dance. As you might know, pretty much every weekend marks at least one on-air amateur radio contest. Following rules set out by a contest the aim is to make contact or a QSO with stations, taking note of each, in a process called logging.
<p>
Using logging software is one way to keep track of who you talked to, a piece of paper is another. If your station is expecting to make less than a dozen contacts per hour, paper is a perfectly valid way of keeping track, but it's likely that most contests expect you to transcribe your scribbles into electronic form. Which electronic form is normally explicitly stated in the rules for that contest.
<p>
While I mention rules, you should check the rules for each contest you participate in. Rules change regularly, sometimes significantly, often subtly with little edge cases captured in updated requirements.
<p>
On the software side, using electronic logging, even transcribing your paper log, can get you to unexpected results. I participated in a local contest and logged with a tool I've used before, xlog.
<p>
Contests often specify that you must submit logs using something like Cabrillo or ADIF. There are contests that provide a web page where you're expected to paste or manually enter your contacts in some specific format.
<p>
Using xlog I exported into each of the available formats, Cabrillo, ADIF, Tab Separated Values or TSV and a format I've never heard of, EDI. The format, according to a VHF Handbook I read, Electronic Data Interchange, was recommended by the IARU Region 1 during a meeting of the VHF/UHF/Microwave committee in Vienna in 1998 and later endorsed by the Executive Committee.
<p>
The contest I participated in asked for logs in Excel, Word, ASCII text or the output of electronic logging programs. Based on that I opened up the Cabrillo file and noticed that the export was gibberish. It had entries that bore no relation to the actual contest log entries, so I set about fixing them, one line at a time, to ensure that what I was submitting was actually a true reflection of my log.
<p>
So, issue number one is that xlog does not appear to export Cabrillo or ADIF properly. The TSV and EDI files appear, at least at first glance, to have the correct information, and the xlog internal file also contains the correct information. Much food for head-scratching. I'm running the latest version, so I'll dig in further when I have a moment.
<p>
In any case, I received a lovely email from the contest manager who apologised for not being able to open up my submitted log because they didn't have access to anything that could open up a Cabrillo file. We exchanged a few emails and I eventually sent a Comma Separated Values, or CSV file, and my log was accepted.
<p>
What I discovered was that their computer was "helping" in typical unhelpful "Clippy" style, by refusing to open up a Cabrillo file, claiming that it didn't have software installed that could read it.
<p>
Which brings me to issue number two.
<p>
All these files, Cabrillo, ADIF, TSV, CSV, EDI, even xlog's internal file are all text files. You can open them up in any text editor, on any platform, even Windows, which for reasons only the developers at Microsoft understand, refuses to open a text file if it has the wrong file extension. This "helpful" aspect of the platform is extended into their email service, "Outlook.com" previously called "Hotmail", which refuses to download "unknown" files, like the Cabrillo file with a ".cbr" extension.
<p>
With the demise of Windows Notepad, another annoying aspect has been removed, that of line-endings. To signify the end of a line MacOS, Windows and Linux have different ideas on how to indicate that a line of text has come to an end. In Windows-land, and DOS before it, use Carriage Return followed by Linefeed. Unix, including Linux and FreeBSD use Linefeed only; OS X also uses Linefeed, but classic Macintosh used Carriage Return. In other words, if you open up a text file and it all runs into one big chunk of text, it's likely that line-endings are the cause.
<p>
It also means that you, and contest managers, can rename files with data in Cabrillo, ADIF, CSV, TSV, EDI and plenty of other formats like HTML, CSS, JS, JSON, XML and KML to something ending with "TXT" and open it in their nearest text editor. If this makes you giddy, a KMZ file is actually a ZIP file with a KML file inside, which is also true for several other file formats like DOCX to name one.
<p>
Of course, that doesn't fix the issues of broken exports like xlog appears to be doing, but at least it gets everyone on the same page.
<p>
Word of caution. In most of these files individual characters matter. Removing an innocuous space or quote might completely corrupt the file for software that is written for that file format. So, tread carefully when you're editing.
<p>
What other data wrangling issues have you come across?
<p>
I'm Onno VK6FLAB
Listen:
Are you up for a global party?
Foundations of Amateur Radio
<p>
Did you know that on the 18th of April, 1925 a group of radio amateurs had a meeting in Paris? During that meeting they formed an organisation that still exists today. Before I get into that, let me share a list of names.
<p>
- Wireless Institute of Australia
- Radio Amateurs of Canada
- Radio Society of Great Britain
- Vereniging voor Experimenteel Radio Onderzoek in Nederland or if you don't speak Dutch, can't imagine why, the Association for Experimental Radio Research in the Netherlands,
- Deutscher Amateur Radio Club, I'll let you figure out what that translates to,
- American Radio Relay League
<p>
Language aside, one of these is not like the other.
<p>
Once upon a time, in a land far, far away, at a moment likely before either of us was born, Hiram, wanted to send a message from his amateur station in Hartford to a friend in Springfield. That's 26 miles, or less than half an hour up the road via I-91.
<p>
One minor problem.
<p>
At the time, in 1914, using amateur radio for anything beyond 20 miles or so was considered a miracle, so Hiram asked a mate at the halfway point in Windsor Locks to relay a message on his behalf. Soon after he convinced his local radio club in Hartford that building an organised network of stations to relay amateur radio messages was worth doing and the American Radio Relay League was born. Co-founded with radio experimenter Clarence Tuska, Hiram Percy Maxim became its first President. He held many callsigns, most recently W1AW.
<p>
At the time, longwave, the longer the better, was considered the pinnacle of communication technology. The airwaves were becoming crowded, so amateurs, in search of more space and always up for a challenge, started experimenting at the edges. The shortest wavelength available to amateurs at the time was the 200m band, or 1,500 kHz. In December 1921 the first successful transatlantic transmissions were achieved. Hundreds of North American amateurs were heard across Europe on 200m and several were heard in reply.
<p>
In a dance that continues to this day, new technology replacing old, spark gap transmitters were replaced by vacuum tubes and using those amateurs were able to use even shorter wavelengths. While technically illegal to operate on higher frequencies, the authorities put their fingers in their ears and let those crazy amateurs play on those useless bands.
<p>
This is a world without international prefixes, no VK, PA or G stations, so amateurs were forced to come up with their own system to indicate the continent and country.
<p>
This was clearly organised chaos at the edges of legality, in many countries amateur radio operation was actively discouraged or even illegal. Soon the same person who came up with the notion of the ARRL led the way and organised a meeting in Paris. That meeting, on the 18th of April, 1925 marks the forming of the IARU, the International Amateur Radio Union and as I said, it exists today.
<p>
That date, the 18th of April is globally, well at least in the amateur radio community, uh, well, small pockets of the amateur radio community, known as World Amateur Radio Day.
<p>
2024 marks the beginning of a year of celebration for the centenary of the organisation that brought together this global rag-tag group of enthusiast experimenters that we fondly refer to as our community.
<p>
The IARU theme for this year is: "A Century of Connections: Celebrating 100 years of Amateur Radio Innovation, Community, and Advocacy" and you're invited.
<p>
So, what types of activities are you planning, what kind of celebration do you have in mind, and who is bringing the birthday cake?
<p>
I'm Onno VK6FLAB
Listen:
What's with all that lack of noise?
Foundations of Amateur Radio
<p>
During the weekend I participated in a contest. Before you get all excited, it was only for a couple of hours over a few different sittings and while I had plenty of fun, of the eleven QRP, or low power, contacts I made, nine were on VHF and UHF, two were on 10m HF. Mind you, 3,200 and 3,500 km contacts are nothing to sneeze at.
<p>
It has been a while since I've actually been on HF, so long that it felt like turning on a new radio and getting used to it all over again. If you're not sure what I'm describing, let me elaborate. A new radio takes a few goes to calibrate your ear and brain to learn what you can expect to hear and work. On some radios if you can hear the other station, you can work them. On others, unless they're pegging the S-meter, you've got no chance. QRP adds an extra layer of challenge.
<p>
A few hours earlier I'd been discussing HF band conditions and one comment that stuck in my mind was that the bands appeared to be more quiet than normal. At the time, nobody could put a finger on why or how, but there appeared to be a general consensus that this was the case.
<p>
So when I tuned to 10m, after having switched off my beacon, which I promptly forgot to turn back on for 36 hours or so, I went hunting for stations to contact. I heard a few, but their signals were very weak. Noise levels were amazing, very quiet, but stations were very low down. I thought nothing of it, given the discussion we'd just had, and persisted and as I said, I made two contacts.
<p>
Since contacts were hard to come by, I started playing with another experiment I'm working on. Specifically I'm using something called USBip to connect to some USB devices across my network. The way it works is that you plug the devices, like a CAT cable and a USB sound-card into a Raspberry Pi, then using another computer, you can access those devices wirelessly as-if they're physically connected to the other computer. This is useful if you don't want to subject an expensive computer to any stray RF that might be coming in via a USB port. I've written some hot-plug support for this, so you can just connect and disconnect USB devices without needing to fiddle. You'll find the code on my github page.
<p>
Given that stations were few and far between and not staying in one place, I moved to a local AM broadcast station, so I could test the USBip sound-card link and all I heard was absolute garbage audio coming from that station. I turned on another radio and it too had the same rubbish audio. After a couple of hours fiddling with RF-Gain and still not getting anywhere I started searching online for an answer. One thread, 27 posts long, seemed to describe what I was hearing. Bill N8VUL supplied the answer: "Make sure AGC is on"
<p>
So, no. It wasn't, on either radio.
<p>
Why it was off on both radios I will never know. It did make me start exploring again just what other settings I have access to on my radio and what they sound like. Turns out that there's not a lot to be found that has any basis in fact. There were a lot of videos showing amateurs pushing lots of buttons uttering phrases like: "Can you hear the difference?" with nothing much materially changing.
<p>
The closest to something useful was a YouTube video by Doug N4HNH, called "ATT, IPO, [and] RF Gain" in which he shows some of the effects of each of those options on a Yaesu FT DX 5000. One thing I noticed is that the radio has a neat display that shows the signal path as it passes from a selected antenna through those options and more, highlighting which ones are in use.
<p>
I started hunting around to see if such a block diagram exists for my FT-857d. Unfortunately I didn't manage to find any such diagram, not even for another radio. The closest I got was the image on page 30 of the FT DX 5000 Series Operating Manual.
<p>
I did learn that the attenuator on my radio is 10 dB and it doesn't function on 2m and 70cm. As for the AGC, the user manual doesn't help much. It states that it's used to disable the Automatic Gain Control and normally it should be left on. There's some discussion around the interaction between the "RF Gain" knob and the AGC, but I must confess that finding useful examples of this managed to elude me.
<p>
At this point I have no idea what the difference is between the block diagram on the FT DX 5000 and my FT-857d, other than the obvious single antenna port and plenty of missing features. I find it surprising that for a radio that was introduced over 20 years ago, this kind of information appears to be lacking. Especially since it would help any new amateur operate their radio better and understand the impact of each particular setting on the signal that they were hearing.
<p>
If you know of any such resource, reach out, my address is cq@vk6flab.com
<p>
Meanwhile I'm going to spend some quality time with my radio and the manual and see what other hidden gems I can find and if you know me at all, you'll know that this isn't the first, second or even third time that I'm going through the manual of a radio that I've now owned for nearly as long as I've been an amateur.
<p>
I'm Onno VK6FLAB
Listen:
The skyhook dilemma ...
Foundations of Amateur Radio
<p>
Whenever I'm out in the bush in the process of erecting some or other wire contraption, uh, antenna, I cannot help but think of the iconic Australian rock band, Skyhooks, not for their glam rock inspired music, nor for their pure mathematics and computer science degree holding guitarist, but for their name.
<p>
In antenna erection, a skyhook is called for when you point at a spot in the sky and will into being an attachment point for the wire antenna in your hand. It's always in the perfect spot, holds any weight and of course it's made from unobtainium.
<p>
Absent a skyhook, there are other ways of hoisting an antenna into the air. A recent discussion revealed that in some places catapults and trebuchets are frowned upon, if not outright illegal. Can't imagine why. Depending on their size, they may be difficult to transport.
<p>
In the same vein, antenna launchers, lightly camouflaged spud guns, are essentially a gas pressurised tube, causing a projectile to be launched by releasing a valve. Those too are pretty restricted and for good reason.
<p>
Fortunately there are plenty of other ways of getting things to be in the right place.
<p>
Let's explore.
<p>
One option is to bring along a pole, made from whatever is at hand, a multi-element fibreglass pole made by Spiderbeam, mine is 12m long, has always worked for me, though I will confess that I have managed to break one. It did take a 135 degree bend in the tip to achieve that. I'll hasten to add, I didn't set out to do that. Previously it had easily sustained 90 degree abuse in heavy wind. I purchased a new one. I've used it for years. It's not cheap, but it works.
<p>
Alternatives, much less strong, are using fishing rods or much less flexible, aluminium tubes, pool cleaning extension poles, even painters poles and at a pinch, lengths of wood screwed together, or if you're a Scout, logs lashed into some contraption.
<p>
Then there's using the nearby landscape.
<p>
Getting a wire into a tree is an activity that's fun for young and old. Not so much for the person attempting it. Often this starts with throwing things at the tree. You might find a spanner, tie it to a rope and whirl it around, letting go at just the right moment to get it to where you're going. This is not a safe activity and not recommended away from emergency medical assistance, you've been warned.
<p>
This graduates to using things like a monkey's fist knot. I was given a brightly coloured one, lovingly hand crafted by Alan VK6PWD. It's reminiscent of a Sea Scout woggle knot. Truth be told, it's too beautiful to use, or rather risk losing. Tie it to a line and whirl and throw. Then there's the arborist throw bag, same deal.
<p>
Each of these whirling activities are fraught. Mainly because you need to strike a balance between the strength of the line, strong enough to be chucked, uh, thrown, but weak enough that you can break it if it gets caught and believe me, it will.
<p>
There's the option of co-opting your dog's ball launcher. Tie a rope to the ball and hurl. Success depends on how quick your dog is in catching low flying tennis balls.
<p>
The last time I went fishing was in 2003 when I used a string and a safety pin to catch an, admittedly, tiny fish at Harry's Hole using a tiny piece of bread, took all of 5 minutes. That said, I have a new fishing rod, well, it was new when I purchased it, but now it's a couple of years old. It was the absolute cheapest one I could find. I also bought a box of sinkers.
<p>
Purchased on the advice of Bob VK6POP, I've used that rod many times to launch a sinker at a nearby tree and used it to pull through some line and then an antenna. It's still a balance between using a fishing line that's strong enough to handle the weight of a sinker and weak enough to break when you want to. The sinker needs to be just the right weight too. Too light and you'll launch it at the right branch where it will stay for the rest of the life of the tree. Too heavy and it will end up somewhere in the bush, never to be found. Grey sinkers tend to vanish in the grass, so if you can find it, look for something nice and bright, fluorescent is best. In a pinch you can use a couple of sinkers, like when you've run out, but in my experience they tend to wrap themselves around a branch.
<p>
Of course you could also just climb into a tree, or hire a cherry picker, but I'm not that flexible, either in my joints or wallet, so those options don't do it for me.
<p>
If you have a friendly arborist nearby, there's no shame in paying them to attach a pulley to the required branch in your backyard. Just make sure that the line you use on the pulley cannot escape the groove and get jammed between the wheel and the cheek, don't ask me how I know.
<p>
So, what ways do you use to summon a skyhook and does it include a Siberian jukebox?
<p>
I'm Onno VK6FLAB
Listen:
Technology at its finest ...
Foundations of Amateur Radio
<p>
So, the 19th of February 2024 came and went. As it was, my day started with the highest minimum that month, 27.5 degrees Celsius, that's the minimum overnight temperature. The maximum that day here in Perth, Western Australia was 42.3 degrees. The day before was the highest maximum for the month, 42.9. If you're not sure, that's over 109 in Daniel Gabriel Fahrenheit's scale.
<p>
That same day the Australian regulator, the ACMA, launched a new era in Amateur Radio. Moving from personal amateur licenses we legally became part of a class license regime. We have the option to hand our license back and get a refund, but the cautious side of me prevailed and I've not yet handed back my license, since it's currently the only proof that my callsign is valid, the one issued to me in December 2010.
<p>
I contacted the ACMA to ask about this and was told that they were having display issues with their system and was sent an image showing both my callsigns and email address. I'm not saying that I don't trust the person sending this to me, but I'm fairly sure that "but your honour, it was in an email" isn't going to cut it if push comes to shove. Curiously my name appears to be missing, showing the word "Blank" instead. Their IT team has been working on displaying F-calls for weeks now. I mean, seriously, these were first issued in 2005. Do we really need to spell this out?
<p>
The ACMA continues to actively encourage amateurs to hand in their license and points out that any delay in doing so will reduce the amount that may be due. It also points at Schedule 4, Part 2 subclause (7)(1)(d) of the Radiocommunications (Amateur Stations) Class Licence 2023, to assure me that my callsign is mine and mine alone, irrespective of what's in the register. It goes on to say that the letter they sent back in January, the one they had to resend, since they got my callsign details wrong, explained that I could hand back my license and that my ability to operate hinged on my qualification, not my callsign.
<p>
Here's the rub. Let's say that I'm qualified and that the letter I have proves it. I am required to identify myself on-air, the regulations say so. This means that in order for me to claim that I am who I say I am, there needs to be a register with that callsign. Apparently I'm in the register, but nobody other than the regulator can prove that.
<p>
One thing that appears to be missing is a solid understanding that the register of callsigns is used by the amateur community to determine if a callsign heard on-air is assigned or not. I mean, I could call myself VK6EEN and without the register who's to say that it's mine?
<p>
It's not confidence inspiring to say the least.
<p>
Then there's the register itself. There's an online component, which you can use to search for a callsign. As I said, mine isn't visible, neither is any other four letter F-call. As a test, I've been scrolling, one page at a time, for the past hour, to get to VK6F, starting at VK6A, to see if it shows up, but I'm not holding my breath. For some reason the developers who built this appear incapable of rendering a simple table in anything less than 36 seconds per page, so much so that Chrome thinks that the page has crashed and offers to kill it, every time.
<p>
Funnily enough, if you extract the URL from within the page and copy it, you can download all 176 pages for VK6 callsigns in less time than it took me to write this sentence. Unsurprisingly, F-calls are not there. Did I mention that this software, released a month ago, is already using depreciated features in my current web browser, which came out a week before the new register went live?
<p>
It gets better.
<p>
If you actually want to manage your callsign, you need to create an account on the regulator's portal, called ACMA Assist. When you load the ACMA Assist URL and click the "Sign up or log in" button, 134 different URLs from all over the Internet are hit, across 34 different domains, including Facebook, Google, Microsoft, LinkedIn, Markmonitor, Monsido, several content, font, icon and javascript libraries, and plenty more. This is a Government website, requiring that I authenticate to it, and to do that, I'm required to provide more identity documents than the tax department needs and wait for it, authentication is outsourced to some random domain, so you're entering your details into a third-party service.
<p>
You have the choice of using the Government identity provider, one that requires a mobile phone and an app, or use a Government owned company that prefers a mobile and a different app, but offers access via a website on yet another domain.
<p>
Now it gets funky. If you pick "driver's license", you'll discover that everything that's on your license is information that the form wants. So anyone with a photo of your license can sign up and identify as you, like the chemist who required a photocopy of it so you could buy Sudafed for your debilitating hay fever, because instead, you might use it to create methamphetamine, or the nightclub that required it so you could enter the venue because of course they do, or the telecommunications company that provided access to your details during a recent hack.
<p>
Just so we're clear here. I'm now required to validate my identity to access a callsign that is already in the database, already has my email address linked to it and is for an amateur license that I already have been in possession of and paid for since 2010. Never mind that I used to email the regulator to have them issue an invoice that I paid for via credit card, no authentication at all, and that was for a personal license, issued specifically to me.
<p>
We'll also ignore that if you signed up with ACMA Assist a year ago, you don't need to validate, not then, not now.
<p>
Speaking of email. The ACMA has just sent me one telling me that I can request and fill in a form and email or fax it to them to update my records instead. That's interesting, but what about the privacy implications of tracking by the worlds mega corporations on a Government site or even the security theatre for something that according to the regulator isn't even my permission to operate?
<p>
I'm all for giving the regulator the benefit of doubt, but if this is the future of Amateur Radio Licensing in Australia, I'm beginning to wonder just which Wild West Orwellian landscape I stepped into and I'm asking myself is this the best that our limited tax payer dollars can achieve?
<p>
If you want to see this for yourself, open up your browser, press F12 and have a look at the network connection tab while you visit the ACMA Assist portal.
<p>
Finally, I have one question.
<p>
Why are our so-called representative bodies, the WIA and RASA, not jumping up and down about this?
<p>
Apparently,
<p>
I'm Onno VK6FLAB
Listen:
The Art of finding an operating location
Foundations of Amateur Radio
<p>
When you operate your station portable, either for fun, or for points, you might be surprised to learn that getting on air and making noise isn't quite as simple as bringing a radio and turning it on.
<p>
Aside from the need for a reliable power supply, batteries, generator, solar panels, or a magic mains socket, there is the requirement for bringing enough gear to get on air, but not so much that setting up takes days, or even hours.
<p>
The decisions you make are influenced by where you decide to operate from. If you want to stay in your car, the location is not nearly as influential as when you decide to find a park where you want to have some fun.
<p>
Finding a location is not a trivial process. If you only plan to get on air for an hour to activate a park, you pretty much get what you find, but if you plan to be on air during a contest for the day, other things start to come into focus. For example, what are the toilet facilities like, are we digging a hole, or is there a public facility nearby?
<p>
Depending on the time of year, the temperature and weather will influence your choice. For reasons I'm still unsure about, most of the contests in Australia are in the middle of summer, so wearing long sleeves, sunscreen and a hat is the starting point for your adventure. Sitting in the midday sun for any period of time, absent a breeze is not fun, so shade becomes a requirement, not a nice to have. Mind you, at least we don't need to contend with meters of snow, well, not where I am. In other words, what works for me might not work for you.
<p>
Finding locations is tricky. You can drive around, consult satellite maps, look for desirable attributes and still be rudely surprised when you get to the point of turning on your gear.
<p>
One of the best lessons I learnt was operating from my car during a contest that awarded points for operating in as many different locations as possible. I used a satellite map to find a location within each boundary and then drove from point to point. If I recall, I set-up in over 30 locations across a 48 hour period. It taught me a great deal about discovering high voltage power lines on a satellite map, the impact of trains on your HF radio, the difference that geology has on your antenna and what a safe location looks like and what the typical hallmarks are for a scary one.
<p>
My most recent discovery tool is a public toilet map. It's not perfect, the user interface is horrid and for some reason it needs to navigate from the Timor Sea to each toilet, but those issues aside, it does help eliminate locations that lack facilities.
<p>
I am in the process of cross referencing the Parks On The Air map with the Toilet map to see if there are some nearby parks that have shade, a loo and the opportunity to park nearby to reduce the amount of lugging required for the gear we intend to bring to the next field day.
<p>
So, what are your tips for finding a place to operate? What kinds of things have you learnt that influence what choices you make?
<p>
Before I go, one pro-tip. Keep a record of where you actually operate and whilst you're at it, what you used, and not. You can thank me later.
<p>
I'm Onno VK6FLAB
Listen:
Getting things done .. or not.
Foundations of Amateur Radio
<p>
Have you ever had a day when nothing you started actually got anywhere? I've had a fortnight like that. Several weeks ago I wrote a couple of articles about emergency communications and its tenuous relationship with our hobby. As a result I managed to get a week ahead of myself and started using that week to do some long overdue analysis of the WSPR or Weak Signal Propagation Reporter data set. I've started this process several times and I finally had a whole fortnight to come to grips with 6.7 billion rows of data. Spoiler alert, it hasn't happened yet.
<p>
The data contains a record of every reception report uploaded to WSPRnet.org since Tuesday 11 March 2008 at 22:02 UTC. It's published in compressed comma separated value text files and after previously spending weeks of wrangling I managed to convert each one into an sqlite3 database. This wrangling was required because some amateurs used commas in their callsigns or grid squares, or backslashes, or both, and SQLite import isn't smart enough to deal with this. After doing this conversion, I could actually query 191 different databases. I could collect the results and three weeks later I'd have an answer, just in time to download the next month of data.
<p>
Garth VK2TTY suggested that I look into parquet as an alternative. No joke, This Changed My Life. I managed to convert all the compressed CSV files to parquet, a process that took a day, rather than a week with SQLite, and then I could start playing. If you're going to do this yourself, make sure you have a big empty hard disk. After a few false starts, the report that previously took three weeks, returned in three hours, and if we're getting technical, since I know this will make at least somebody laugh, the parquet files are stored on a USB drive connected to an iMac that has the directory mounted via sshfs to a virtual Linux desktop machine that's running the duckdb binary inside a Docker container running on a different virtual Docker machine. If you're keeping track, the database travels across USB via two SSHFS mounts to duckdb and it still only takes three hours. So, impressed doesn't even begin to describe my elation. If you're asking "why?" - the answer is that I don't run untrusted binary executables on my host machine.
<p>
This allowed me to start doing what-if queries when I discovered a fun issue. A chart I generated with minimum, average and maximum power levels over time showed that there was at least one station that was claiming that it was transmitting with 103 dBm. For context, that's multiple times the power of HAARP, the High-frequency Active Auroral Research Program which in 2012 was the most powerful shortwave station using "only" 95.5 dBm, or 3,600 kilowatts, and only 2 dBm shy of the 105 dBm or 32 megawatts used by AN/FPS-85, part of the US Space Force's Space Surveillance Network, able to track a basketball-sized object 41,000 km from Earth.
<p>
In other words, 103 dBm is less of a whisper and more of a roar. Funnily enough, not every receiver on the planet reported these transmissions, but more than one did, so the issue is at the transmitter. Unfortunately, when I started looking for reports using more than 60 dBm, there were plenty to choose from, over 18 thousand. While that's less than 0.0003%, it made me wonder how much of the data is dirty and what should I do about it?
<p>
There's other examples of dirty data. My beacon has been reported on 24 MHz, which is odd, since my licence conditions do not permit me to use that band. Odder still is that several other beacons, normally on 28 MHz like me, were also reported on 24 MHz by the same station. How often does that happen?
<p>
I've previously reported the missing data from the hybrid solar eclipse in 2023, just under two hours and 12 minutes before the eclipse and the 38 minutes following it was missing. I've not yet checked to see if it magically reappeared.
<p>
Then there's the faulty decodes. I've talked about this before. Different WSPR versions are better or worse at decoding and the point at which it breaks down varies. In other words, some decoded data is inevitably wrong.
<p>
I have previously charted activated grid squares. Apparently, all of Earth, yes, all of it, has at one time or another been used both as a transmission or reception site. Including point Nemo, the top of Mount Everest, all of the arctic and antarctic and plenty more out of the way places, like say the Surveyor Generals Corner located in the Ngaanyatjarraku shire - look it up. Interesting patterns emerge when you split activations down per band. It's not clear if those are decoding artefacts or man made claims.
<p>
I've asked the HamSci community for guidance, since dropping incorrect data on the floor doesn't seem to be the right way to go about things, and whilst correcting data seems obvious, what do you change it to and how do you know what's correct?
<p>
So, no progress to show for two weeks of work and barely enough to whet your appetite to get on air and make some noise.
<p>
Some days are like that.
<p>
I'm Onno VK6FLAB
Listen:
Writing to the regulator about amateur beacon and repeater licenses.
Foundations of Amateur Radio
<p>
A few weeks ago I discovered that the regulations for amateur radio in Australia had some definitions that caused me to wonder if 2,312 amateurs in VK, me among them, had been operating illegally?
<p>
Specifically it appeared that using a WSPR or Weak Signal Propagation Reporter transmitter of any kind, both computer controlled and stand-alone beacons, was contrary to what was permitted in the rules, since in Australia an "amateur beacon station" means a station in the amateur service that is used principally for the purpose of identifying propagation conditions.
<p>
The rules go on to say that you must have a specific beacon license and not having one is not permitted.
<p>
I suggested that it was time to send a letter to the regulator, seeking clarification.
<p>
Well, let me tell you, that set a cat among the pigeons, not at the regulator, but within the amateur community. Between posting a draft of my proposed email to a local mailing list before sending it to the regulator, and publishing my article, I received responses that ranged from "let sleeping dogs lie", "you are now on their radar", "you will be prosecuted because you admitted to breaking the rules", "carry on and ignore the rules because I am", and plenty more in that same vein.
<p>
There were two amateurs that indicated curiosity about what the response might be while pointing out that none of this was legally binding since it hadn't been tested in court.
<p>
I also discussed the matter on my weekly net and I learnt that DMR hotspots come in a duplex version, meaning that what you transmit into the hotspot is also transmitted by the hotspot on RF whilst sending it to the Internet. If you've been paying attention, you'll notice that this fits the definition of an "amateur repeater station", which also requires a specific license.
<p>
I received a prompt reply from the Australian Communications and Media Authority, the ACMA, the Australian regulator. Here's what the regulator had to say in response to my query:
<p>
"I can confirm that you can continue to operate your WSPR beacon and Duplex Hotspot as described without requiring an Amateur Beacon or repeater licence."
<p>
It goes on the say:
<p>
"Operation of these types of amateur equipment is permitted under the current amateur non assigned arrangements and as such will continue to be permitted under the class licence arrangements."
<p>
As a result, if you've been listening to WSPR on 10m, you'll have discovered that my 10 dBm beacon went back on the air 45 minutes after receiving this information. The letter confirms that both WSPR and Duplex hotspots have previously been, and will continue to be, allowed under the new rules from the 19th of February 2024 when they come into effect.
<p>
The final paragraph from the regulator sets out the boundaries of where the rules apply. It says:
<p>
"The definitions in the Interpretation Determination are broad definitions of amateur repeaters and beacons. For the purposes of amateur licensing the ACMA only considers apparatus assigned licence services, where individual frequency coordination is carried out and specific licences are issued, to be amateur repeaters and beacons."
<p>
In my opinion this is significant because you only need to apply for a separate amateur beacon or repeater license in very specific circumstances related to frequency coordination. It makes me wonder if the local beacon operators require an ongoing license for all of their beacons or not.
<p>
What I learnt from this process is that there is a high level of fear in the amateur community towards the regulator. I do not know where this originates, since I've interacted with the regulator on dozens of occasions since obtaining my amateur license in 2010 and in every case the response was courteous and informative. When the response wasn't what I expected I replied asking for extra clarification and received it. This enquiry was no different.
<p>
Going back through decades of old publications I've previously seen letters between the community and the regulator and I have yet to see anything that warrants the level of fear that appears to permeate our community.
<p>
So, why are we afraid of the regulator and why do we keep spreading that fear to anyone within propagation range? What have they ever done to you?
<p>
I'm Onno VK6FLAB
Listen:
What is amateur radio as an emergency response?
Foundations of Amateur Radio
<p>
I recently discussed some of the notions of amateur radio as emergency response. The idea that you might jump into the breach and be a hero is appealing and often celebrated.
<p>
The American Radio Relay League, or ARRL, proudly tells the story of two amateur radio emergency communication events. One, of a person who fell in their bathroom and happened to have a handheld radio that they used to contact another amateur who contacted emergency services. The story goes on to say that being part of the Amateur Radio Emergency Services or ARES had taught the amateurs the ITU phonetic alphabet, as-if that's not a requirement for getting your amateur license. Then there's the story of two teenagers who were critically injured in a remote area and amateur radio rescued them due to a contact with a random local amateur. Never mind that there was a local off-duty EMT who actually stabilised the patients.
<p>
While you might point at this as "amateur radio to the rescue", to me this is a case of people attempting to make the story about amateur radio. If the person in the bathroom happened to have a mobile phone nearby, the story would not have even made the nightly news and if the people in the remote area had actually prepared properly, they'd have had an emergency position-indicating radiobeacon or EPIRB and a satellite phone, rather than accidentally bumping into a random radio amateur.
<p>
Moving on. Have you ever noticed that your mobile phone stops working after a couple of hours during a power outage? It's because mobile phone towers run on batteries that depending on load might last up to 12 hours, often much less than that, anywhere from down when the power goes out to 3 hours until the batteries fail. Note that I'm not talking about the battery in your phone, I'm talking about the ones in the tower serving your phone.
<p>
I mentioned previously that there was a network outage affecting 40% of the Australian population. The get-out-of jail card was that the rest of the population still had mobile, landline and internet connectivity. What would happen if the other network operator also went down?
<p>
Is there a place for amateur radio in those scenarios?
<p>
Let's explore. If all mobile, telephone and internet networks were down, what would that look like? Could you call an ambulance or the fire department using amateur radio? Who would you talk to, on what frequency and on which radio would they be listening? Would you set up your portable shack in the local hospital or fire station? Would ambulances and fire services be able to coordinate during such an outage, or would you have your local amateur club ride-along on every ambulance and fire truck?
<p>
What does such a system look like in actuality? Has there been any planning or training for this? Are there refresher courses and special certifications? Does your local community have anything like this in place, or are you starting from scratch?
<p>
During widespread and long lasting fire emergencies in Australia, radio amateurs have acted as emergency services radio operators. There is at least one amateur club where, years ago, the members underwent special training with the local State Emergency Services to learn their language and procedures, just in case it becomes short staffed when an actual emergency occurs.
<p>
I've often said that doing contests is a good way to learn how best to operate your station and how to work in adverse environments with lots of interference, man-made or otherwise. The reality is that it's more likely than not that you'll be using a line-of-sight FM radio in the emergency services communications bunker than sitting in the rubble of your shack using HF with a wire antenna running off battery trying to get someone, anyone, to help you and your community.
<p>
There are official amateur radio emergency organisations, WICEN in Australia, ARES and RACES in the United States. Much is made by these organisations about joining and training, but very little in the way of actual emergency response. Is that a marketing issue, or are these types of organisations obsolete and waiting to be disbanded?
<p>
My point is this.
<p>
If amateur radio is really a service as the WIA states, "A Trusted Partner in Emergency Response", or as the ARRL puts it, "When All Else Fails", even making that a registered trademark, where is the evidence of their activity, where are the annual reports, the after action lessons learnt, the inter-team competitions, the talks at local clubs, the league tables of emergencies handled, lives saved and babies born?
<p>
To give you insight into just how broken this is, any licensed amateur can become a member of ARES, but you can only read their newsletter if you're a member of the ARRL. In Australia, for a while, the WIA offered a course for Public Safety Training for Radio Amateurs, but only to amateurs with an Advanced license, which I discovered after spending $633.92 to print out, collate and bind the 973 pages of course material, as-if those of a lesser amateur radio qualification somehow were less able to read a map, operate communications equipment, follow defined occupational health and safety policies and procedures, work effectively in a public safety organisation, as part of a team, or in an emergency operations centre.
<p>
So, what's your plan for providing amateur radio as a service?
<p>
I'm Onno VK6FLAB
Listen:
What is the right mode for emergency communications?
Foundations of Amateur Radio
<p>
Amateur radio is an activity that falls between two camps, those who think of it as a service and those who approach it as a hobby.
<p>
I think that the notion of amateur radio as a service is often repeated, but in my time as part of this community, I've seen little evidence of actual service. That said, the idea of amateur radio as a service is often linked to emergency communications, for example, a phrase used by the Wireless Institute of Australia is "Amateur Radio - A Trusted Partner in Emergency Response" on a page outlining the long and fabled history of our hobby in service to the community in times of emergency, mind you, none of them in the past decade.
<p>
If we look at the idea of amateur radio as an emergency response, what does that look like today and how might we best be of service?
<p>
The question that prompted this discussion centred around the best mode to use for emergency communications and was presented in the context of a tool that links HF radio with email, but is that really the best way to communicate in an emergency?
<p>
I mean, picture this, you're on a boat in the middle of the ocean, it's the small hours of the morning, you're asleep, and your boat just sailed into a submerged container and now you're sinking, so the first thing you do is, fire up your laptop, your radio, and link the two to send an email over HF to get help?
<p>
Alternatively, your community has just been hit by a natural disaster and the power grid went down, and the first thing you do is use as much battery hungry complex technology as possible to get the word out?
<p>
So, until we can send email or a short message directly from our amateur radio transceiver, and I have no doubt that some bright spark is working on that, there are better ways to make contact in case of an emergency.
<p>
From a mode perspective, at the bottom of the pile is Morse code. I say bottom, not because it's a poor way of communicating, but it doesn't require much in order to get working. You could essentially use a car battery and splatter your emergency communications around. One downside is that you'd need to learn Morse code and while you're in the middle of an emergency is probably not the best time.
<p>
If you're on a sinking boat in the middle of the ocean, you're likely going to use a HF radio, or an emergency beacon, or even a satellite phone, but if you're on land, dry or not, and if you're not an amateur, your best bet is to find a 27 MHz AM Citizen's Band radio, so you can make enough noise to have people come and find you.
<p>
The reality, more likely than not, is that emergency services are outside the danger zone waiting for authorities to permit entry.
<p>
It should be clear by now that there are several levels of emergency communications before we get to amateur radio. That said, if you have an amateur radio, then you're likely going to use voice communications over SSB on HF or FM on VHF or UHF.
<p>
Now you might ask about communications going the other way, from outside the emergency zone, where power and sunshine are plentiful, where you can use a computer without issues. Only thing is that if it's all peaches, why are you attempting to link your radio to HF when on the balance of probability there's a mobile phone sitting in your pocket?
<p>
A couple of months ago there was a 12 hour network outage at one of the two main telephone networks affecting nearly 40% of the population of Australia. It was recently revealed that during that time almost 2,700 people could not call emergency services on either their mobile or land-line, let alone use the Internet.
<p>
You could argue that this is an actual emergency, but is amateur radio really the vehicle for making contact? I mean, you're trying to call emergency services, your phone isn't working, so rather than use a telephone on another network, you go and find your nearest radio amateur and ask them to call for an ambulance, on their HF radio?
<p>
Where does this leave us?
<p>
In my opinion, the notion that your shack is going to be used for emergency response is fanciful. That's not to say that there isn't a place for radio amateurs. Far from it.
<p>
If you really want to be of service, learn how to operate your radio well, make a plan to work through if you hear a distress call while you monitor emergency HF frequencies, visit the local emergency services to see if they offer training for radio amateurs and make yourself available in case of emergency and you're more likely to be of service than if you sat in your shack polishing your valves.
<p>
If you're so inclined, planning for the next emergency, start asking questions. Find out what the plans are for your emergency AM broadcast network, learn how things might break and perhaps then you might consider amateur radio as a service to the community, just not in the way you might have thought.
<p>
Next time I'll explore the reality of amateur radio as an emergency response.
<p>
I'm Onno VK6FLAB
Listen:
What is a repeater or a beacon ... really?
Foundations of Amateur Radio
<p>
The other day I came across an amateur who expressed concern that someone was using a frequency set aside for repeater use with their hotspot. Band plan issues aside, and you are encouraged to send an email to cq@vk6flab.com with the link to the official band plan that applies to your DX entity, in my experience it's not unusual for an amateur who is configuring their so-called hotspot to use such a frequency.
<p>
While you might be familiar with the concept of a mobile phone hotspot that allows you to connect a computer through your phone to the Internet, in this case we're talking about an amateur radio hotspot. Similar in that it allows you to connect through the device to the Internet, but different in that this is essentially a device that connects radios to the Internet, and yes, if we're being pedantic then computers and mobile phones also have radio, well spotted.
<p>
Anyway, an amateur radio hotspot is a radio with an Internet connection and in that it's much like a modern repeater. Often they use low transmit power, have limited range within a building or vehicle and because of that are hardly "unattended". That said, if you connect a more effective antenna and an amplifier, you could make such a device into a full blown repeater. In other words, the line between hotspot and repeater is likely in the eye of the beholder.
<p>
Given that the regulator in many countries requires a license for operating a repeater, or a beacon, I wondered what the official definition of a repeater was, so I went looking. Note that this applies to Australia only, but you'll find the journey illuminating I'm sure.
<p>
The current "Radiocommunications Licence Conditions (Apparatus Licence) Determination 2015" does not have either the word repeater or beacon.
<p>
The new "Radiocommunications (Amateur Stations) Class Licence 2023" which comes into effect on the 19th of February 2024 uses both repeater and beacon several times but does not define what they are. It has an interpretation section with a note that lists both "amateur repeater station" and "amateur beacon station" and states that the regulator can define terms under section 64(1) of its own act.
<p>
The "Australian Communications and Media Authority Act 2005" section 64(1) states that "The ACMA may make a written determination defining 1 or more expressions used in specified instruments, being instruments that are made by the ACMA under 1 or more specified laws of the Commonwealth." It should come as no surprise that neither repeater nor beacon appears in this document.
<p>
I then thought to go sideways and search the "Register of Radiocommunications Licences" for a repeater license. It reveals a PDF for a license with all manner of detail, frequencies, power levels, location, antenna type, etc. for a license, but no definition of what a repeater is.
<p>
I then looked at the 481 pages of the "Radiocommunications Act 1992". It uses both beacon and repeater. Unfortunately beacon is in relation to the operation of lighthouses, lightships, beacons or buoys. Repeater is in relation to two or more digital radio multiplex transmitters.
<p>
I then searched through the "Federal Register of Legislation" for the phrase "amateur beacon station". It returns 27 results of which 9 are in force. I downloaded all 9, including any explanatory text if it was available. In all, 340 pages of legal documents.
<p>
Finally we have progress. In the "Radiocommunications (Interpretation) Determination 2015" we find the following definitions:
<p>
"amateur beacon station" means a station in the amateur service that is used principally for the purpose of identifying propagation conditions.
<p>
"amateur repeater station" means a station established at a fixed location:
(a) for the reception of radio signals from amateur stations; and
(b) for the automatic retransmission of those signals by radio.
<p>
So, if your hotspot is in a vehicle it's not a repeater, but if you have it sitting in your shack, it is.
<p>
Similarly, apparently, my 10 dBm WSPR transmitter, which I use solely for the purpose of identifying propagation conditions, is a beacon. Apparently if you have your computer controlling your radio using WSPR, that's a beacon too. You can apparently apply for a license and pay the regulator for the privilege, the price of which went up by 510% according to their own documentation from $29 to $177, no idea if that's a once off or an annual charge.
<p>
So, now we have a situation where, apparently, the rules state that I'm not permitted to use WSPR without a beacon license. In fact, the "Explanatory Statement to the amateur class licensing reform instruments" explicitly states that "Subsection 13(2) prohibits the operation of an amateur station for specified purposes, including for the purpose of obtaining a financial gain or reward. The subsection also prohibits the operation of an amateur beacon station or an amateur repeater station under the Amateur Stations Class Licence, and, subject to subsection (3), the transmission of an encoded signal to obscure the meaning of the signal."
<p>
I've just hit send on a letter to the regulator asking for clarification. Perhaps you should write one too.
<p>
I've also just switched off my WSPR transmitter and if you're one of the 2,312 amateurs who made a WSPR transmission last year in Australia, perhaps you should too.
<p>
I'm Onno VK6FLAB
Listen:
New arrangements for Australian Amateur Radio
Foundations of Amateur Radio
<p>
From the 19th of February 2024, the ACMA, the Australian Communications and Media Authority, the regulator, is modifying the rules for amateur radio in Australia by moving to an amateur class license where all amateurs will operate under the same license instead of under an individual one.
<p>
You must be qualified to operate under the new class license and all currently licensed radio amateurs should now have been issued with a recognition certificate for their current qualification level.
<p>
Keep this certificate safe, it authorises you to operate as an amateur and shows which callsigns you currently hold. I've just received a revision that now correctly identifies my callsign VK6FLAB as a four-letter callsign, rather than three-letters which caused concern over the longevity of my call.
<p>
There's no annual charge to operate as an amateur, no charge to keep a callsign, and no charge to do an exam, however, if you operate a repeater or beacon, you'll continue to require a transmitter license. There are once-off charges for applications to consider and issue recognition certificates and callsigns but those are not new.
<p>
The document that legally defines amateur radio in Australia, colloquially the LCD, is replaced by the Radiocommunications (Amateur Stations) Class Licence 2023. The regulator carefully states that: "To operate an amateur station under the amateur class licence, you must comply with the conditions within it", but doesn't clarify if those conditions have changed or not. External commentary claims they haven't, but it was completely re-written and it's difficult to compare the precise actual wording side-by-side.
<p>
This has happened before, for example, when the regulator introduced the Limited license in 1954, the Novice license in 1975, abolished Morse in 2004, and introduced the Foundation, Standard and Advanced licenses in 2005. It was replaced again in 2015 and has been revised since, most recently on the 17th of November 2021.
<p>
I suspect lawyers will find potentially unintended but material differences between documents, but to my knowledge, that investigation has not yet occurred. I think this is a perfect example of where the peak bodies claiming to represent amateur radio in Australia have a responsibility.
<p>
There are many rules around the who, how and where to conduct a qualification exam. For example, the regulator has decided that online or residential exams are not permitted, leaving venues, printed exams and postal delivery as an ongoing cost and concern.
<p>
There are plenty of questions left.
<p>
An amateur at Advanced level can hold a club station callsign but it appears that at a Foundation or Standard level you can no longer hold a club station license like VK6BSG and VK7HSD. You still need to log usage of a remote club station. Describing the requirements the regulator uses both "revise their arrangements" and "current arrangements will be retained" in the same paragraph, apparently contradicting itself.
<p>
The regulator will ask you every five years if you want to keep your callsign. This infers a system to contact you. What does that look like, how will it be maintained, are there requirements for keeping it current, does it need to have the location of your station, an email address, or just any means of contacting you, and is it public? The official register of radio communication licenses will no longer hold amateur licenses so it's unclear how you'll be able to contact another amateur, or how we'll be able to know who holds which callsigns at what level in which location and when a reminder is due. The details around the new callsign register are incomplete to say the least.
<p>
What does breaking the rules look like? With individual amateur licenses your ability to operate is directly linked to you and if found in breach, your license can be cancelled. Under a class license, your ability to operate hinges on knowledge that cannot be taken away.
<p>
The regulator publishes the relationship between some international amateur licenses and qualification levels in Australia and as an international visitor you can apparently operate in Australia for 365 days if your current license is recognised. After that, unless you hold a Harmonised Amateur Radio Examination Certificate or HAREC, you need to apply for a recognition certificate after either paying for recognised prior learning or passing an exam, even though you were already automatically recognised as having the appropriate qualifications when you entered the country. Does the list of recognised licenses get longer as more international amateurs pay for prior learning and if you leave the country and return, will the clock reset?
<p>
There's more. For example, the date that you got your US Technician license determines your recognition. Before 23 September 2016 you're recognised at an Australian Advanced level, after that at a Foundation level.
<p>
And finally, if I were an accredited unpaid volunteer assessor, authorised to administer an amateur exam on behalf of the regulator, would I be permitted to comment like I am here, or would I be expected to speak directly with the regulator about my concerns? What happens if speaking directly to the regulator breaks down? What's the penalty for speaking out? Is the regulator going to stop you from being an unpaid volunteer?
<p>
Before you ask why I didn't put these concerns to the regulator, I'll point out that it's not up to me to fix these issues, nor is it my place to make recommendations. I don't represent anyone and in my opinion this should be a community wide public conversation, not held in secret talks behind closed doors.
<p>
As an amateur outside Australia I'd recommend that you pay attention, because I'm sure that bean counters will be taking notes to see if there's money to be saved at your regulator.
<p>
I'm Onno VK6FLAB
Listen:
How to see 56 MHz of bandwidth...
Foundations of Amateur Radio
<p>
The other day I stumbled on a project called Maia SDR by Daniel EA4GPZ. Maia, spelled Mike Alpha India Alpha, is a star in the Pleiades cluster. The Maia SDR project homepage proclaims that it is "An open-source FPGA-based SDR project focusing on the ADALM Pluto".
<p>
Now, I can completely understand if that collection of words is gibberish to you, but take it from me, it's not, let me explain.
<p>
PlutoSDR or Pluto is the common name of a piece of hardware which is officially called the ADALM-PLUTO Evaluation Board. It's a sophisticated device made by Analog Devices that provides a radio platform with some very interesting properties. Specifically it's both a radio transmitter and receiver with the ability to use frequencies between 70 MHz and 6 GHz. It runs embedded software you can tinker with because it's all Open Source and it's all very well documented.
<p>
Many people have used the Pluto as a remote transceiver by controlling the on-board radio with a USB cable. While that's neat, it's not what I have been wanting to do for a number of reasons.
<p>
The Pluto has the ability to sample data at a rate of 61.44 mega samples per second or MSPS. That translates to a bandwidth of 56 MHz. A typical amateur radio has a bandwidth of 2.5 kHz.
<p>
This bandwidth comes at a price. For starters, USB on the Pluto isn't fast enough to handle 56 MHz of data, so if you're using it as a remote radio over USB, you need to lower your expectations.
<p>
However, the hardware itself can process data at that rate, as long as it stays inside the radio. So, if you had a way to process data inside the radio and a way to show what you did with the data across USB, you could use all of the 56 MHz at once.
<p>
The Maia SDR project does exactly that. It processes the data and presents it to the world as a waterfall image, like the one you might have seen in WSJT-X, fldigi or SDR++. If you've seen the voice version of my podcast on YouTube, you'll also have seen a waterfall. It's an image that scrolls vertically, showing frequencies left to right, and signal strength by colour, traditionally, a rainbow that uses blue for low power and red for high power. Every time period the image scrolls adding another row representing the radio spectrum at that time. It's a very useful way to show massive amounts of radio spectrum data in close to real-time.
<p>
The waterfall that WSJT-X produces is about 2.5 kHz wide. The waterfall that Maia SDR produces is 56 MHz wide. To give you some context, the entire HF spectrum, between 2200m and 6m easily fits within 56 MHz.
<p>
Now, there's a wrinkle. As I said, the Pluto frequency range starts at 70 MHz, so that means we can't use it to listen to HF. Well, not without the help of another gadget, called a transverter. Essentially it moves a set of frequencies from one range to another. The gadget I have, a SpyVerter 2 HF Upconverter, translates anything between 1 kHz and 60 MHz and moves it to between 120 MHz and 180 MHz.
<p>
If you combine the Pluto with Maia SDR and a SpyVerter, you can plug your antenna into the SpyVerter, connect that to the Pluto, connect to the Maia SDR website that's running on your Pluto, tune it to 120 MHz, and see 56 MHz of HF bandwidth scrolling past as fast or slow as you want. You'll find the 10m band at 148 MHz, the 15m band at 141 MHz and the 20m band at 134 MHz.
<p>
Now if that's not cool enough for you, Maia SDR is as I said Open Source. This means that the project publishes all of the code that makes this happen. The Pluto comes with a number of devices on-board that process information. At the antenna end is an AD9363, essentially a chip that converts RF into digital and back. The digital information is processed by a device called an FPGA, a Field Programmable Gate Array. Field Programmable means that mortals like you and I can change the software that it runs.
<p>
Essentially an FPGA is a programmable circuit board used for information processing. To scratch the surface of what that means, you could for example program an FPGA to behave like a microprocessor, or you could use it to do accelerated matrix multiplications used for neural networks like you can with a graphics chip, or in this case, a device that does all of the digital signal processing. Finally the Pluto has a dual core ARM processor. You'll find those inside most Android phones and Raspberry Pi's to name a few. It's used to extract data from the FPGA and present it on a web page. Oh, and there's a progressive web app for your phone, so you can see this waterfall on your mobile phone if you want.
<p>
So, thank you to Daniel EA4GPZ for sharing your project, it's very much appreciated!
<p>
There are some caveats. The Pluto is easily overwhelmed by strong signals, so you probably need filters. I'm using a wide 2m band pass filter between the SpyVerter and the Pluto, just so that my local WiFi network doesn't overwhelm the whole thing. You're receiving between 0 and 56 MHz, so you'll need an appropriate antenna. The frequency response for the Pluto isn't linear, so the same colour on two bands might not be the same signal strength. You need to update the firmware of the Pluto, so make sure that you have a copy of the official firmware before you start because some of the FPGA functionality has been removed by Maia SDR to make this stuff work, most notably, the ability to use the Pluto across USB as a remote radio which is restored if you re-install the official firmware.
<p>
It's all documented really well and I'd encourage you to have a go if you're so inclined. If you're a software developer, Maia SDR aims to encourage FPGA development in the radio sphere using Amaranth, the project About page has more details.
<p>
As random Internet searches go, Maia SDR was a lovely surprise and I can't wait to dig deeper, but that will have to wait until my computer stops processing something like 6 billion WSPR records, which it's been doing for the past two weeks.
<p>
What have you found worth sharing?
<p>
I'm Onno VK6FLAB
Listen:
The Art of operating QRP
Foundations of Amateur Radio
<p>
The attraction to amateur radio for me lies in the idea that it provides a framework for experimentation and learning. There's never an end to either. Each time you go on-air is an opportunity to do both and every chance I get, I cannot help being sucked into another adventure. My weekly scribbles are an attempt to both document what I've been up to and to encourage others to take a step on the path that I'm discovering, moment by moment, week by week.
<p>
One of the more, lets call it, comment inducing, activities I like to explore is low power operation. This is not to the liking of many operators who are happy to run their shack at full legal power. For me, full legal power is 40 dBm, or 10 Watts. That's not to say that I've never experienced the thrill of running a pile-up on a contest station, I have. What's not to like? You speak with people from communities far-and-wide, they're clamouring to talk to you and making contact is pretty easy, almost effortless. The lure towards more power, bigger antennas, more bands and more radio is always there, but it's not all there is to this hobby.
<p>
My year-long efforts of running a 10 dBm, or 10 mW, Weak Signal Propagation Reporter, or WSPR, beacon, is evidence that you can make it 13,945 km from me in VK6 to PA where it was heard by Jaap, PA0O in Zuidwolder, just outside Groningen in the North East of 't kikkerland. In fact, across 2023, my 10 dBm beacon was reported 4,849 times by 58 stations, many inside Australia, but there were reports from Indonesia, Japan, New Zealand, Taiwan, Antarctica, Sweden, and as I said, the Netherlands.
<p>
One of my friends, Charles NK8O, is a mostly mobile operator who loves to set up for both Parks On The Air, also known as POTA, as well as World Wide Flora and Fauna, WWFF. His chosen mode is CW, but you'll find him using digital modes like FT8 and even as a rare DX event you might strike it lucky and hear his voice. Most of his activity uses batteries, so you'll rarely make contact with him when he's using more than 47 dBm or 50 Watts. A couple of weeks ago during the weekly F-troop net he announced that for the duration of 2024, Charles intends to operate using low power, or QRP.
<p>
Operating QRP isn't for everyone, but I'd hazard a guess that if tried, there's plenty to learn and experience by dialling the power down to play in a low power environment. Think of it like this. If you're into cars, it's the thrill of driving fast. It's not the only way to drive and enjoy yourself. Driving sedately, touring the back roads, will get you to your destination just as well and along the way you'll have the opportunity to look out the window, to even have the window down and to enjoy the environment, rather than spending every second being on a hair trigger.
<p>
If fishing is more your thing, high power radio is like dynamite fishing. You'll easily catch all the fish in the pond, but once you have, there's nothing left to do. Fly fishing on the other hand gets you a different but perhaps just as satisfying experience.
<p>
So, if you've never done this QRP thing, what can you expect when you turn the power down? First of all, reception works just the same. So, everyone you heard before will continue to be heard. Transmission is going to be a little different. If you've ever changed over radios you might already have experienced the jolt between what you can hear and what you can work which can differ significantly between two radios. If you're used to high power operation, you'll essentially work most stations you can hear, but when you're using low power, there's going to be stations that you have little or no chance to work. Most of those are obvious so-called alligators, all mouth, no ears. That said, plenty of loud stations have years of honing their skill and station and your QRP call can just as easily be heard as the next station.
<p>
You'll likely sharpen your calling skills. There's no point in calling when other stations are blotting out your call, so you become adept at dancing around other signals. You'll spend more time considering propagation and the best band to make your signal count.
<p>
Another side effect you'll likely notice is less wear and tear on your gear. There's also little chance of having RF inside your shack upsetting your computer, or getting complaints from the neighbours who happen to have a crappy TV that stops working as soon as you key up. If you make mistakes, your station is more forgiving and less likely to be damaged when an unexpected fault occurs.
<p>
Speaking of faults. The other day a coax switch in my shack caused my radio to stop transmitting. Luckily with the power setting at its lowest, there was no permanent damage. After testing with a multimeter I discovered that it shorted the centre pin to shield in one position. When I opened up the switch, I discovered that the blade that gets moved between ports had become slightly twisted, which in turn caused it to ground against the body. A slight turn with some needle-nose pliers fixed the problem, well, at least for now. I have begun searching for alternatives in earnest. I am quite taken by the notion of building my own switch from relays and controlling those via a network connection. More research and experimentation is needed because there's plenty I don't know about this subject.
<p>
Between you and me, it's never too late for another experiment and I'd encourage you to spend some time testing the QRP experience and given the current state of the solar cycle, there's no better time than right now.
<p>
I'm Onno VK6FLAB
Listen:
Finding the right frequency.
Foundations of Amateur Radio
<p>
Today I'm going to spend a little longer with you than usual, but then, I think this is important and it's good to end the year on a bang.
<p>
Have you ever attempted to make contact with a specific DXCC entity and spent some time exploring the band plan to discover what the best frequency might be to achieve that? If you got right into it, you might have gone so far as to attempt to locate the band plan that applies to your particular target. If you have, what I'm about to discuss will not come as a surprise. If not, strap yourself in.
<p>
When you get your license you're hopefully presented with a current band plan that is relevant to your license conditions. It shows what frequencies are available to you, which modes you can use where, and what power levels and bandwidth are permitted. It should also show you if you're the primary user or not on a particular band. If you're not sure what that means, some frequency ranges are allocated to multiple users and amateur radio as one such user is expected to share. If you're a primary user you have priority, but if you're not, you need to give way to other traffic.
<p>
It should come as no surprise that this is heavily regulated but as a surprise to some, it changes regularly.
<p>
Across the world, frequency allocation is coordinated by the International Telecommunications Union, the ITU, and specifically for amateur radio, by the International Amateur Radio Union, the IARU. It coordinates frequencies with each peak amateur radio body. The ITU divides the world into three regions, Region 1, 2 and 3, each with its own band plan. Within each region, a country has the ability to allocate frequencies as it sees fit - presumably as long as it complies with the ITU requirements. As a result, there's not one single picture of how frequencies are allocated.
<p>
And this is where the fun starts.
<p>
In Australia there's an official legislated band plan, cunningly titled F2021L00617. It contains the frequencies for all the radio spectrum users as well as a column for each ITU region. The document is 200 pages long, and comes with an astounding array of footnotes and exclusions. It's dated 21 May 2021. There's a simplified version published by the Wireless Institute of Australia, which comes as a 32 page PDF. It was last updated in September 2020. When I say "simplified", I'm of course kidding. It doesn't include the 60m band which according to the regulator is actually an amateur band today. The 13cm band according to the WIA shows a gap between 2302 and 2400, where the regulator shows it as a continuous allocation between 2300 and 2450 MHz. The point being, who's right? What can you actually use?
<p>
Oh, the WIA does have a different page that shows that 6m "has had some additions", but they haven't bothered to update their actual band plan.
<p>
To make life easier, the regulator includes helpful footnotes like "AUS87". This is particularly useful if you want to search their PDF to determine what this actually says, since it only appears 156 times and it's not a link within the document. In case you're curious, it's related to three radio astronomy facilities operated by the Commonwealth Scientific and Industrial Research Organisation, better known as the CSIRO, two by the University of Tasmania and one by the Canberra Deep Space Network. Interestingly the Australian Square Kilometer Array and the Murchison Widefield Array don't feature in those particular exclusions, they're covered by footnote AUS103.
<p>
If that wasn't enough. The regulator has no time for specific amateur use. You can find the word Amateur 204 times but there's no differentiation between the different classes of license which means that you need to go back to the WIA document to figure out which license class is allowed where, which of course means that you end up in no-mans land if you want to discover who is permitted to transmit on 2350 MHz.
<p>
If we look further afield, in the USA the ARRL publishes half a dozen different versions, each with different colours, since black and white, grey scale, colour and web-colour are all important attributes to differentiate an official document. Of course, those versions are now all six years out of date, having been revised on the 22nd of September 2017. The most recent version, in a completely different format, only in one colour, has all the relevant information. It shows a revised date of 10 February 2023, that or, 2 October 2023 because of course nobody outside the US is ever going to want to refer to that document - seeing as there's only amateurs in the USA, well at least according to the ARRL.
<p>
Interestingly the US Department of Commerce, the National Telecommunications and Information Administration, Office of Spectrum Management publishes a colourful chart showing the radio spectrum between 3 kHz and 300 GHz. You can't use it as a technical document, but it's pretty on a wall to amaze your non-amateur friends. The FCC has a band plan page, but I couldn't discover how to actually get amateur relevant information from it.
<p>
If you think that's bad, you haven't seen anything yet.
<p>
The British are special. The RSGB publishes a variety of versions, each worse than the next. It appears that their system creates a single HTML page for each band, their 32 page PDF is a print out of that and their interactive viewer wraps all that into some proprietary system that makes using it an abysmal experience. Fortunately, they also link to a band plan made by the regulator, presented as a five page PDF which is much more concise and has the helpful heading: "The following band plan is largely based on that agreed at IARU Region 1 General Conferences, with some local differences on frequencies above 430MHz."
<p>
Unfortunately it doesn't specify which particular General Conferences apply, but it does helpfully tell us that it's effective from the first of January 2023, unless otherwise shown. That said, 2023 only appears in the headers and footers and 2024 doesn't appear, so who knows what date exceptions exist.
<p>
One point of difference is that the RSGB also publishes their band plan as an Excel Workbook. This might start your heart beating a little faster with visions of data entry, sorting, filtering and other such goodies, like figuring out which frequency to use for a particular mode. Unfortunately the authors have used Excel as a tool for making tables like you'd see in a word processing document. Start and Stop frequencies in the same cell, random use of MHz, spacing between bandwidth and frequencies and descriptions intermingled. In other words, this is not an Excel Workbook and it does not contain information in any usable form, unless you want to do some free text searching across the 32 worksheets - what is it with 32 anyway? Perhaps this is their authoring tool and they save as HTML from within Excel or print to PDF. Who knows?
<p>
One point that the British do get right is version control. You can see specifically what change was introduced when. For example, on the 6th of March 2009 the 17m QRP frequency was corrected to 18086 kHz. Mind you, there's several pages of updates, helpfully scattered across multiple worksheets. Yes, they're really using Excel as a word processor.
<p>
Before I dig into any other countries, I should mention the United Nations Amateur Radio peak body, the IARU, presumably a model that countries should aspire to. The IARU has links to three different sets of band plans. Region 1 breaks the band plan into HF and higher frequencies and the higher frequencies are broken into notional bands, each with their own PDF. Regions 2 and 3 each provide a single PDF, but the Region 3 document is hosted on the Region 2 website. Region 1 documents contain a revision and an active date as well as an author. Region 2 and 3 documents contain a date and are formatted completely differently.
<p>
In Germany the DARC attempts to link to the IARU-Region 1 band plan, but the link is pointing at a non-existent page.
<p>
In the Netherlands, VERON points at a 2016 edition of the IARU-Region 1 HF band plan and the current Region 1 mixed band plan for higher frequencies.
<p>
In Canada the RAC points at a HTML page for each band and presents all the HF frequencies as a single image, yes an image. All the other bands are essentially text describing how to use a particular band. The HF image states that it applies from the first of June 2023, the rest of the pages carry various dates that conflict with each other. For example, the 2m band states on the landing page that it was updated on the 23rd of September 1995, but the page itself refers to a new 2m band plan that was approved in October of 2020. The linked band plan contains all the credit, who is responsible for the plan, naming the entire committee, adding notes and requesting donations, straight from the RAC newsletter, page 36 and 37 of the November / December 2020 edition, rather than providing a stand-alone technical document.
<p>
Let's hop back across the Atlantic and see what else we can learn.
<p>
In Switzerland things are a little different. Its regulator publishes a frequency allocation plan that is a thing of beauty. It presents as a table on a web page, but it has a search box you can use to filter the frequencies that you're interested in. So if you use the word "amateur", you end up seeing the whole amateur radio spectrum as it exists within the borders of Switzerland. You can also set frequency ranges and as a bonus, if you type in 1 MHz and change the unit to kHz, it actually changes the number to 1000. As I said, a thing of beauty. Oh, and the footnotes? Yeah, they're links and they open a new window with the relevant information, and you can keep clicking deeper and deeper until you get to the actual legislation driving that particular entry. If that's not fancy enough for you, from within the search, you can download an offline HTML copy, you can pick services, rather than use search terms, and the PDF version, because of course there is one, actually has the same active links to footnotes.
<p>
That said, it has some idiosyncrasies. It specifies when amateur radio is the primary or the secondary user of a band, except when it doesn't. I presume that this is a regulatory thing and that it's a shared resource, but as an outsider I'm not familiar with Swiss law, but if I was inclined, I could become familiar, since the documents are all written in multiple languages, including English. Another oddity is that some frequencies show no text at all, but I presume that's a bug, rather than by design.
<p>
Speaking of bugs, or features, depending on your perspective. Consider the frequency 2300 MHz. Every single document I looked at mixes up how this is shown. Some have a space between the number and the unit, some don't. Some countries put a space between the 2 and the 3, some a dot, some a comma, the Swiss use an apostrophe. Just so we're clear, these are technical documents we're talking about. They're not literary works, there are standards for how to do this, but it seems that the people writing these documents are blissfully unaware of any such references. Even the IARU cannot agree on how to represent the same number, let alone use the same formatting for the same band plan in each of its three regions.
<p>
At this point you might come to the conclusion that this is all an abhorrent mess and I'd agree with you. In my opinion, it goes directly to how important our hobby is in the scheme of things and just how little funding is allocated to our activities.
<p>
It also shows that there are contradictory sources of truth and not a single unified view on how to present this information to the global amateur community. In case you're wondering why that matters, electromagnetism doesn't stop at the political boundaries of the location where we might find ourselves and if that doesn't matter to you, consider again how you'd best talk to an amateur of any given DXCC entity and on what particular frequency you might achieve that.
<p>
So, aside from whinging about it, what can you do about this?
<p>
I have started a project, of course I have, that attempts to document two things, well, three. First of all I use the WIA version of the DXCC list - since the ARRL doesn't actually publish that for free anywhere - and use that to track a list of hopefully official frequency allocation documents. I'm also in the process of capturing the content of each of those documents into a database, so we can all figure out what the best frequency is to talk to another country.
<p>
I'm still in the design stages for the database, for example, do we want to store a frequency in Hertz, in kHz, or pick a magnitude and store a number? Each of these choices has long term implications for using the tool. Then there's things like discovering which band plan applies to Scarborough Reef, the San Felix Islands and Pratas Island to name a few, since I've really only scratched the surface with the plans I've explored.
<p>
I had visions of putting this on GitHub, but perhaps this should be part of the Wikipedia collection and it should live there. I'm still considering the best plan of attack. In the meantime, you can help. Please send an email to cq@vk6flab.com with the official band plan link for your own DXCC entity, and if you have thoughts on how best to structure the database or where this project should live, let me know.
<p>
For example, should the database include just band plans, or should we also include things like modes. For example, the official VK calling frequency for 40m is 7.093 MHz. Should that be in the database and should we include the preferred Olivia calling frequency? While looking at that, consider the band labels we use. Australia doesn't have a 75m band, but others do. Some countries refer to the 4mm band, others refer to it by frequency.
<p>
So, over to you. Let me know what you think. I'll leave you with a quote by Daren 2E0LXY:
<p>
"It is not the class of licence the Amateur holds but the class of the Amateur that holds the licence."
<p>
I'm Onno VK6FLAB
Listen:
It's the little things ...
Foundations of Amateur Radio
<p>
Walking into your shack is often a joyous experience. You take a moment to smile at your setup and, at least mentally, rub your hands in glee anticipating some fun. Well, that is how it is for me, but recently it's been less of that and more of an audible groan at the accumulated cruft that makes it nigh on impossible to sit down, let alone achieve anything fun.
<p>
It's not as bad as it could be. I'm forced to keep my station at least operational to host my weekly net, but if that wasn't there, it would have been overtaken by anything and everything finding a flat surface to put stuff on. It got to the point where I had to move some radio equipment off my desk, just so I could pile more stuff onto it.
<p>
So, on Tuesday I finally had enough. It was a pretty normal day, waiting for others to get stuff done, deadlines be damned, but I took one look at the shack and snapped. This has happened before and I suspect that it will continue to happen throughout my life, but that day I'd crossed the line.
<p>
Before I share what I achieved, I should mention a couple of other things. If you've been here for a while you'll know that I am an unashamed computer geek. Software Defined Radio, or SDR, appears to have been invented just for me, embedded computers, digital modes, networking, data analytics, Linux, Docker, you name it, I'm there. Mind you, this isn't new. It's been true for nearly forty years now, ever since I set foot into my high-school computer lab where I found myself looking at a bank of Apple 2 computers. Then I bought the first computer in my class, a Commodore VIC 20. Life was never quite the same.
<p>
This to tell you just how much computing features in my day-to-day.
<p>
I have a long term plan to use embedded computers like for example a Raspberry Pi to essentially turn my analogue Yaesu FT-857d into a networked SDR. The idea being that I use my main computer to do the processing and the Pi to control the radio and feed the audio in and out across the network. I want to make it so that you can use any traditional SDR tool with such a radio, and if I get it right, any other radio.
<p>
For more context, I'm getting more and more deaf. I swear my SO is speaking softer each day and hearing tests tell me that audio above 2 kHz is pretty much gone. I have been playing with audio signal processing with a view to tailoring the audio coming from my radio into something more audible to me.
<p>
On Tuesday I had an ah-ha moment. I could keep waiting until I got all that done and then set-up my shack just so, or I could embrace the analogue nature of my gear and use the mixing desk I have to feed the audio through its on-board audio processing and at least improve my audio experience today, rather than some nebulous future time.
<p>
Finally, I purchased a peg board some time ago for the specific purpose of strapping my coax switches to so I would not have to contend with coax all over my desk whilst trying to remember which switch did what when I finally had a moment to play.
<p>
All this came together in a new version of my shack, albeit an alpha pre-release, to be treated with extreme caution, if you break it, you get to keep both parts and it will kill a kitten without notice.
<p>
To get started, I removed all non-radio stuff from my desk. Including half a dozen computers, a dozen patch leads and adaptors left over from the harmonics testing project, there were monitor cables, USB cables, a variety of power supplies and a stray binder with empty pages.
<p>
I found all the radio gear that I really wanted to have on my desk, placed it where I could actually use it and figured out how to connect the audio output from each radio to the mixing desk which also found a home.
<p>
Then I jumped on the RF side of things. Getting started was the hardest part. I decided that it would make sense to split the peg board in two, one half for HF, the other for VHF and UHF. I have two coax switches that I use as the entry point onto the board. They're each fed with the antenna coax and each have one port connected to the other. The idea being that during a thunderstorm I can connect the two antennas to each other and isolate the rest of the shack. It won't protect against an actual direct hit, but all charge being built up should dissipate between the two antennas. Feel free to give me suggestions on how better to do this in a shack located on the second floor of a house in Australia. Note that the rules for grounding across the world are drastically different, so don't assume that your laws apply in Australia.
<p>
The HF coax side has a strapped down Bias-T which powers the SG237 antenna coupler that's outside. Then there's a switch so I can connect HF to a radio or to a beacon, which I also strapped to the peg board. On the VHF side there's just a second coax switch to select between two radios, but only one is currently connected. I plan to strap my PlutoSDR to the other port.
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I powered everything up and couldn't trigger the local repeater. I got out my handheld and tried. That worked fine. I could even hear it on my main radio, but it wouldn't trigger. No SWR issues, I could hear local broadcast stations, but still couldn't trigger the repeater. It took an embarrassingly long time to discover that I had managed to feed the HF antenna into the VHF/UHF side. The SWR was fine because it was triggering the SG237, so, fun.
<p>
On the audio side I can now change the compression of a signal, change the low, mid and high frequencies and if I feel inclined change the balance between my ears. Microphone is via the hand microphone, for now. There's no CAT control at the moment and I still need to plumb in the push to talk, or PTT, foot pedal. I also need to move the peg board so RF cables aren't dangling in the breeze, but overall, a massive improvement and best of all, I turned on my radio and it wasn't even Saturday morning.
<p>
So, what's your excuse for procrastinating?
<p>
I'm Onno VK6FLAB
Listen:
The visibility of our radio community.
Foundations of Amateur Radio
<p>
Cars have been here for well over a century and so has radio. Cars pretty much start when Carl Benz first applied for a patent for his "vehicle powered by a gas engine" on the 29th of January 1886 which is regarded as the birth certificate for automobiles. Radio starts as a thing when Heinrich Hertz proves that radio waves exist in 1888.
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Since then things have changed, a lot.
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Today, both these technologies, cars and radio, are everywhere. It's estimated that there are 1.47 billion vehicles on the planet today, in contrast, there are only 44 thousand broadcasters across the globe, serving about 4 billion people, or half the population. So, cars win, right?
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Not so fast. The Wi-Fi Alliance estimates that there's 3.8 billion Wi-Fi devices being shipped this year alone and there's about 19.5 billion in use. Many of those are mobile phones, so they're not only using Wi-Fi, but GSM, CDMA, 3G, 4G or 5G radios. In many cases they'll have Bluetooth on board and will be receiving GPS information from the currently five constellations in orbit around Earth. Some will even have an FM receiver on board, just to cram another radio inside the same box.
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To give you a better sense of scale, 2022 saw 4.9 billion Bluetooth devices shipped. In 2010 it was estimated that there were a billion GPS users, today there are more than six billion users being served by GPS systems for positioning, navigation and precision timing.
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I haven't even talked about other uses of radio, like radar, astronomy, remote sensing, remote control, keyless entry and countless other related and interconnected technologies.
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So, while there's a car for every five or so people, there's at least two Wi-Fi radios per person and probably more like a dozen radios per person when you start counting those embedded in our daily lives.
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So, why is it that we have an estimated car enthusiast population of 10% and an estimated radio amateur population of 0.04%?
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It's not to do with the popularity of the topic. Google trends shows that both cars and radio are consistently trending downwards at about 2% each year since 2016. Radio is consistently twice as popular as cars. When you rank the global popularity of cars vs radio, out of 47 countries, 40 countries care more about radio than cars.
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South Africa and India care about cars 74% to 26% radio, even New Zealand, 56% vs 44%, cars to radio. At the other end of the scale, Peru, 2% cars, 98% radio. Germany, home for both Heinrich Hertz and Carl Benz, 92% radio, 8% cars.
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Popular search engines aside, there are other places to look for content. Take platforms like Prime Video, Netflix, Apple TV+ and YouTube.
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When you search for radio or cars on those platforms it's interesting to see what comes back and explore how relevant it is. I'll encourage you to do the experiment, but as a surprise to nobody, the results are universally woeful but illustrative. Searching for cars returns mostly relevant content, but a search for radio brings back results that have absolutely nothing to do with the topic. Seriously, on Netflix, two documentaries about Pele and Beckham, both famous footballers, neither known for their interaction with radio, rank higher than a documentary on Prime about radio astronomy, cunningly titled, wait for it: "Radio Astronomy".
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Even the initially promising Netflix result "Amateur" in response to the term "radio" is about a 14 year old basketball player navigating the dark side of sports. While we're at it, just for giggles, I checked the closed captioning for the movie and the word "radio" doesn't appear in the movie, at all. Speaking of representation, Netflix recently published their entire list of content for the first half of the year. The word radio appears exactly once, "John Mulaney: Kid Gorgeous at Radio City" and that doesn't even turn up as a search result when you go looking for "radio". The word "cars" appears 18 times in the Netflix library.
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So, why is it that topics like "radio", which is demonstrably twice as popular as "cars", and perhaps a dozen times more, let's call it, numerous, in society, has such a poor showing and what can we as connoisseurs on the topic of "radio" do about this?
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Cars are represented in a plethora of movies, series and shows featuring reviews, mods, restorations and entertainment. There's topic specific channels and social media. There's shops, events, races and so much car merchandise. Is that what's missing in radio, or more specifically, amateur radio, marketing, or is it something else? I'm keen to hear your thoughts. My email address is cq@vk6flab.com, get in touch.
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For my efforts, I'm publishing my podcast on YouTube and manually working my way through my back catalogue of over six hundred episodes, complete with a, YouTube imposed, limited five thousand character summary of the transcript, just to increase the chances of radio being a relevant search result when someone who's interested in our community comes looking.
<p>
I'm Onno VK6FLAB
Listen:
Report on Radio Harmonic Power
Foundations of Amateur Radio
<p>
There is a perception in the community that the hobby of amateur radio is an expensive way to have fun. While it's entirely possible to spend thousands of dollars on equipment, in much the same way that it's possible if your preferred hobby is golf, getting started does not have to require that you start planting money trees.
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Lots of fun can be had using cheap amateur radio transceivers that are used all around the world. If you do start with such a radio, the chances are good that you'll come across amateurs who make disparaging remarks about the lack of compliance of such radios.
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When I say compliance, I'm talking about specific measurements specified by the International Telecommunications Union, the ITU. When you transmit on a specific frequency, there are rules about how much that signal is allowed to be unintended, or to use the official term, spurious emissions.
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Specifically, the signal you transmit has to meet the requirements for the mode you're using and it must also stay within limits on other frequencies. For example, if you have a 2m handheld radio that uses FM, the transmitter must stay within the required width for FM and it's not allowed to transmit above a certain level on any of the harmonic frequencies.
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When someone claims that all cheap radios are non-compliant, they're saying that such radios are either not transmitting a valid FM signal, or that the levels of the signal exceed the limits specified by the ITU.
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Given that such radios are in wide use, Randall VK6WR, Glynn VK6PAW and I got together to see if we could come up with something a little more scientific in the way of comment about such radios. With access to Randall's HP 8920A RF Communications Test Set we came up with a repeatable way to test a radio and then went to the local HAMfest where we subjected a pile of radios to our tests. In total we did 75 tests. Overall we tested 39 distinct models across 12 brands.
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So, what did we learn?
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All so-called "name brand" radios were fully compliant.
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All radios that were sold in Australia by Australian distributors were compliant.
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Baofeng radios made up the largest sample of inexpensive radios. Seven out of the 26 tested were compliant, eight were non-compliant and the rest, 11 were borderline. More on that shortly.
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We also tested many radios that had been purchased online. We didn't test enough of each model to make specific comments, but it's worth pointing out that half of all the online radios were compliant.
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Now, I mentioned borderline compliance. What we learnt was that there were some radios that fell within 6 dB of being compliant. The HP test set hasn't been calibrated for a while and we felt that allowing for a 3 dB random measurement error and a 3 dB systematic error would prevent us from marking a radio non-compliant when in fact it was. We categorised 16 radios as borderline.
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Our report is of course public. You can find it on my GitHub page as both a PDF and a markdown document.
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Whilst we were writing our report, we discovered uncorroborated suggestions that some radios might fail an emissions test after suffering unspecified damage in the output filtering stages. We looked at the schematic of one radio that suggests that a simple capacitor failure might cause a filter to fail without preventing the transmitter from operating.
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This might mean that a non-compliant transmitter might be made compliant again by replacing the faulty capacitor. We haven't tried and we don't know if a failed capacitor actually makes a radio non-compliant or not, or even if such a failure could occur and if-so, how.
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In other words, this might be a red-herring, we just don't know.
<p>
One other comment worth pointing out is that it was suggested that some radios might use a specifically designed antenna to suppress the second harmonic. Given that some radios failed only on the second harmonic spurious emission requirement, but not the third, this seems plausible. All radios we tested had removable antennas and were tested without an antenna, since compliance relates to the transmitter, not the antenna. It does raise a more interesting question. What happens if you fit a different antenna to the radio?
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One adage that stands is that "you get what you pay for", but given the amount of cheap testing equipment available, it's relatively easy to test every handset in your shack.
<p>
I'm Onno VK6FLAB
Listen:
What about promoting the hobby?
Foundations of Amateur Radio
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Amateur radio is an activity enjoyed by many people around the world. How many exactly is cause for debate. The most recent official figure we have is from the IARU, the International Amateur Radio Union. In 2020 it counted over 3 million people, but an article written a year later puts that figure at 1.75 million.
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In Australia there's a common narrative that the total amateur population is in undeniable decline, some think that it's on a stark decline. Interested in hard data, for years I've been collecting information around the amateur population in Australia and I can report that across the nine years that I have data for the total variation is within two percent and it's not a straight line down either. There was a dip in 2020, potentially associated with training and callsign allocation being moved from the Wireless Institute of Australia to the Australian Maritime College, something which is going to change again shortly when amateur licensing in Australia will revert to the regulator, the Australian Communications and Media Authority. If you're familiar with amateur licensing in Australia, that's not the only change, but that's not what I'm looking at today, mainly because the available information associated with the upcoming changes are limited at best, seemingly buried in invective at worst.
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Back to the topic at hand. One of the often heard responses in relation to the decline of our hobby is recruitment of new amateurs. It's a topic that I've spent plenty of time over the past decade contemplating. How do you share the joy of amateur radio with a general public who is apathetic to the preconceived ideas associated with this hobby, you know, old white men sitting in the dark with Morse keys.
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For the record, I prefer a shack with light and I still don't know how to use a Morse key, other than to make my radio beep. The rest is genetic.
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In the quest for spreading the word there's a repeated emphasis on the young, often coalescing around the annual Jamboree on the Air, or JOTA, as organised between Scouting groups and radio amateurs. I have previously said that JOTA was how I first came across amateur radio, but at the time, aged 15 or so, I had no money for such endeavours and the experience didn't resonate with me until decades later. So, you could argue that this is what changed me into an amateur, but the reality is that I had to come across the hobby a few more times before I got interested enough to investigate, something which I have spoken about before, in short, Meg, then VK6LUX introduced me to the concept of controlling a 2.4 GHz drone using higher power than was permitted with standard Wi-Fi equipment. I was hooked and got my license less than a month later. I then discovered that I needed more permissions and set about studying, only to get distracted with everything I could already do. I'm still being distracted today.
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So, JOTA is a potential touch point, but I see little evidence that the initial spark goes anywhere in a hurry. I'm not dismissing it as a way to have amateur radio gain relevance outside our own community, but perhaps there are other ways to make this happen. In the early days of my journey I attended country fairs with my club and we'd set-up a radio or six to show and tell. There was talk of doing this in a shopping centre, at the local hardware store and even brief discussions about doing this at the local electronics store. As enjoyable as this was, none of it ever appeared to generate any permanent interest and I don't recall seeing new amateurs suddenly appear at the club after any outings.
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Last week Glynn VK6PAW and I, set-up at the local airport, YPPH, that's Perth International Airport if you're not familiar with the designation allocated by the United Nations arm, ICAO or the International Civil Aviation Organization. Perth has a public viewing area. It's situated at the south western end of runway 03/21. It's an elevated position with minimal shade, some seating and you're 320 m from the runway centreline. It's a place where plane spotters congregate and now a few radio amateurs.
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One thing we have in common is an interest in radio. We were told that the plane spotters often listen to one or two frequencies and if they're into video, they might record one radio channel to include on their YouTube videos. When Glynn and I visited we had a few radios with us. When I say few, in amateur terms we only had about five or so, but I suppose that comes with the territory. As it happens, admittedly not by accident, our radios could receive airband frequencies, so we could tune to Perth Tower, Perth Arrival, Perth Ground, Perth Departure and Melbourne Central, all at the same time. Next time we'll likely bring some HF gear so we can also listen to HF aviation frequencies as well.
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While I was hosting F-troop, the weekly net for new and returning amateurs, midnight UTC, every Saturday morning for an hour, Glynn was busy talking and sharing with the plane spotting community. There were conversations around what radios and antennas to use, how you could tune to more than one frequency at the same time, how you could use software defined radios, how to set-up radios so you could have different channels appear at the left or the right, in the middle, or somewhere in between, which will allow you to focus on a particular radio call as it happens. Also, I should mention a piece of software called rtl-airband which allows you to use an RTL-SDR dongle to do this at home, but I digress.
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There was a steady stream of people looking at planes and their age was surprising, aged 3 to 93 or so. Of course not all were into the radio, but plenty were.
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Afterwards it occurred to us that there might be other venues like this, attracting people who are interested in radio for their own purposes. I have no doubt that we'll be back to Perth Airport, but I suspect we'll also see if we can find some other spotters. Train, ship and other airports come to mind immediately. I can't wait to learn about other people's uses and interests in radio, even if radio isn't the main attraction in their hobby. Perhaps you can think of some that you'd like to share.
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Getting on air and making noise is one way to get outside, but publicly listening to frequencies that others are interested in is a perfect excuse to play with radios.
<p>
I'm Onno VK6FLAB
Listen:
Spontaneously getting out and about ...
Foundations of Amateur Radio
<p>
For years I've been hosting a weekly net called F-troop. It's a one hour opportunity for new and returning amateurs to get together and share their questions, and sometimes answers, about anything and everything amateur radio, with side trips into astronomy, electronics, circuit boards, testing gear and whatever else takes our fancy on the day. The net runs for an hour every Saturday morning starting at midnight UTC, which for some is a time when they're fast asleep, though truth be told, several of our regulars are night owls.
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In VK6 where I am, midnight UTC is a more reasonable 8am, unless we have another referendum when we can decide if we want daylight saving, or not. So far we've had four of those, yes, really, in 1975, 1984, 1992, and 2009, and each time daylight saving or summer time was rejected. All I'm saying is that the chances are good that midnight UTC is going to be 8am in VK6 for a while yet.
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Anyway, that time of the morning affords me the luxury of getting out of bed at a sensible hour, having a shower, making a cup of coffee with my Significant Other, or SO, and ambling into my shack to get ready. It's a comfortable process, something I've done for over 12 years with very little in the way of variation with the exception of the 500th and 600th episodes which I hosted outdoors at a local radio club, complete with BBQ and many visitors. That and the Friday Night Technical Net with Reg VK6BQQ, but that's a story for another day.
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Last week a good friend, Glynn VK6PAW, asked me if I wanted to go out and have some fun, and having been pretty much cooped up for several years now, of course I said "yes". We're going to the viewing platform at the Perth International Airport, that's airport code YPPH, where I'll host the net in whatever way we figure out at the time. It's not an event, we haven't told anyone about it, and telling you now won't ruin the surprise for anyone, since this weekly rambling hits the airwaves after F-troop concludes. I knew there was a reason.
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Anyway, at this point you have every right to ask me, "Onno, why should I care?"
<p>
Indulge me and let me see if I can explain.
<p>
Most, if not all, of my amateur radio activities are planned. From time-to-time I might get in my car and drive to a nearby park and get on HF, but truth be told, I haven't done that for several years. I have regularly told you about contests I've done, often whilst operating portable, often with friends, but sometimes alone. I have activated all manner of things, climbed summits, played in parks, gone to lighthouses and other such places. Every, single, time, those activities were planned, often to within an inch of their life. What should I bring? Where am I going to set-up? What gear do I need? What spares are required? What logging tool is needed? Will I need food and water? You know, a typical 7p activity, Proper Planning and Preparation Prevents Piss Poor Performance.
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This time the plan consists of: "Do you want to go to the airport?" and "Sure!"
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Mind you, that's in the context of Glynn normally having several radios in his car and me not having a clue what to expect. The other day I actually had my first ever look at the location in Google Street View, only to discover that there's a shelter there, so hopefully we won't fry in the forecast 38 degrees Celsius, that's 100 degrees in Ray Bradbury's temperature scale, if you're wondering.
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Now, on the whole, this is a pretty low risk activity. Nobody is going to die if I don't manage to get the net going, though I do have Echolink on my phone, which reminds me, I should probably check if that still works. I'll put a pencil and a notepad in my pocket for logging and I'll bring a bottle or six of water and probably some coffee. Sorry, I can't help myself.
<p>
In other words, it's entirely possible to get on air and make noise without having to go to the Nth degree of planning and still have fun. As it happens, fun is something that's been in short supply of late, so, that's also a welcome change.
<p>
As an aside, in a completely unrelated and random observation, I recently installed a new font on my computer, called Hack. It's mono-spaced, sans-serif, intended for source code, and licensed under the MIT License. I'm using it right now and I'm in love. So secretly, between you and me, that's what goes for fun around here. Oh, in case you're wondering, no, I did not get paid to say that, the authors have no idea I exist, unless they're unexpectedly radio amateurs, I'm just a happy user.
<p>
Also, if you're wondering about Echolink, no need to fret. I just tested and it just works straight out of the box. Gotta love that.
<p>
Now, here's a question for you. When was the last time you spontaneously got on air to make noise?
<p>
I'm Onno VK6FLAB
Listen:
Failure to simulate ...
Foundations of Amateur Radio
<p>
During the week I started a new project. If you know me at all, this is not unusual. Having worked in the IT industry for nearly 40 years it's also not unusual that projects have a way of surprising you and this project was no different.
<p>
Recently I've been talking about antennas, a topic close to the heart of many amateurs and one that garners a lot of opinion and in my experience, much less in the way of facts, so being a firm believer of facts, I set out to add some of those to the discussion.
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After having described that the environment is not often discussed in the context of antenna behaviour, coupled with the personal experience that it has by far the biggest influence, I set out to discover if I could use my computing skills to simulate this problem to build a picture that would speak a thousand words. Prompted by a friend who shared with me a link to an opinion that stated that dipole antennas didn't have 2.15 dBi gain, but in fact, apparently, had 8.5 dBi gain, I was energised to find out where this number came from.
<p>
I figured I'd spin up some antenna modelling software, use a standard model of a dipole, then simulate it at various heights above the ground and see what I could learn. Any good journey starts with a single step, so I started with looking for a generic model of a dipole antenna. I've played in this space before, so I was familiar with the fact that most, but not all, antenna modelling tools use a piece of software called NEC2 to do the actual calculations. Its models are described using text files ending in the .NEC extension. This software goes back to punch card days, so the format for the NEC2 files is essentially a stack of punch cards, so much so that every line in the text file is called a card and any software that uses the underlying NEC2 tool describes it in that way.
<p>
I won't bore you with the syntax, it's, let's put it this way. If you've been around computers for as long as I have, you're familiar with a tool called "sendmail", which is known to be user-friendly, just very particular with whom it makes friends. The NEC2 card format is much the same. It's not that surprising, and for added nostalgia, NEC2 was written in FORTRAN, originally in 1981 at the Lawrence Livermore Labs by Jerry Burke and Andrew Poggio. It was later released to the public. There's translations to C and C++, but they use the same notion of cards, so no magic progress there.
<p>
I started learning the syntax, and eventually came across a text-book with an example of cards that describe a dipole. Mind you, there were plenty of disclaimers around how poorly the ground was simulated and wouldn't you know it, the file format uses meters as the dimension, rather than wavelengths, so as far as I can tell, you can't simulate a quarter wave antenna, you have to simulate one of a specific length, so much for using a standard model of a dipole.
<p>
I found a tool that uses Python to issue NEC2 commands and as a surprise to nobody, it too uses cards. I used it to discover that for a particular type of ground, at some unknown height, the optimum length for a 10m WSPR dipole antenna is 5,225.87 millimetres long, apparently. You know it's true, it says so right there on the screen. I'm skipping over having to compile the software that was supposed to be a ready made Python library, but I digress.
<p>
There was a tool, written in TCL, that visualised NEC2 output, last updated 18 or so years ago and I unsuccessfully tried to make it work. Then there were those who suggested to fire up some random Windows tool on my Linux box, but as far as I can tell, I'd have to do the height adjustments manually, not ideal if you want to visualise from say, ground to geostationary orbit, one millimetre at a time and output an image at every step.
<p>
I searched the net for others who would surely have trodden this path long before I came along, only to discover that my search-fu is clearly broken, or any website with promising information has long ago been booted off the Internet, leaving "For Sale" signs on the domain name.
<p>
I came across one file which simulated a dipole in free space. It had, to use the NEC2 terms, 11 cards. When I run that through "nec2c", it generates a 12 megabyte file with over 104-thousand lines of output. Only takes 650 milliseconds to generate. If only I could visualise it.
<p>
I also came across a whole range of physics programs, which is not that surprising, since essentially antenna design is physics, but those tools require that I start learning a whole new way of building antennas, apparently from electrons, preferably whilst getting a degree in physics with a specialisation in computational electromagnetics. Then there was the Wolfram Alpha notebook model for a simple dipole, only 3,200 lines of code, so, you know, trivial to use.
<p>
So, here's the thing. Has nobody in living memory simulated a dipole at more than three heights and documented the process? Am I really the first human on the planet to think of this?
<p>
Oh, yes, I did find a project that simulated different lengths of dipoles, but I'll leave those for another day. And finally, I also found "xnecview", which does generate images, but it too is very particular whom it makes friends with and I've yet to discover if it can generate what I'm looking for.
<p>
As for the 8.5 dBi, I'm still looking. My current best guess is that at some specific height a dipole has an ugly spike that has 8.5 dBi gain and that someone used that number without looking at the detail, but, who knows, there's plenty of opinion to go around.
<p>
I'm Onno VK6FLAB
Listen:
Let's compare the same antenna in different locations...
Foundations of Amateur Radio
<p>
Let's compare the same antenna in different locations...
<p>
Over the years I've spent many hours building and testing antennas. I've talked about this and discussed how there is essentially an infinite variety of antennas that can exist. To give you a sense of this, picture a basic dipole antenna, two bits of wire, same length, connected to a feed-point. We're doing this experiment in space, so we're not concerned with trees or rope, or the ground for that matter, more on those shortly.
<p>
We can make this dipole straight, or we can make it into a V-shape, or bend over the edges, or make each side into a half-circle and join them, or make them into a spiral, or kink the wires, or bend them over, or any number of variations. Every time you change something, the antenna radiation pattern changes and the antenna behaves differently. While at its heart the antenna might still be considered a dipole, essentially a change in radiation pattern effectively means a different antenna.
<p>
In those changes or wire orientation alone we have already defined an infinite number of antennas, but that only scratches the surface. We can build an infinite variety of physical antennas. Consider the design of vertical antennas, loop antennas, log periodic antennas, yagi antennas, slot antennas, and beverage antennas to name a few.
<p>
Once you start investigating antennas you'll discover just how many options there are and once you've acquired the antenna of your dreams, the work is only just beginning.
<p>
To explain why this is the case, consider the process of finding an antenna to buy or build. You'll find breathless reports of how amazing an antenna is and how it allowed the operator to hear a mosquito land on the back of a container ship in the middle of a tropical cyclone whilst the sunspot activity was at an all time low. Right next to those reports you'll find another amateur describing how their dummy load performed better and cost less.
<p>
If not those specific examples, you'll have no doubt found both positive and negative reviews for the very same antenna, often side-by-side and if you don't, you're not looking hard enough.
<p>
Leaving aside the notion that someone is trying to discredit a commercial competitor or that the antennas are inadvertently physically different, because someone put it together incorrectly, there's plenty of opportunity for other reasons for this wide range of opinion.
<p>
Let's take the popular G5RV antenna, invented in 1946 by Louis G5RV, who became a silent key on June 28, 2000. The antenna is a multi-band HF antenna and there are plenty of people offering plans and kits for this antenna. Ignoring the differences in plans, let's imagine that two amateurs purchased the exact same G5RV from the same batch from the same supplier. Both erect their antennas at their home shack, or QTH and get on air to make noise. At a local BBQ they get together and compare notes only to discover that the two antennas are behaving completely differently.
<p>
How is this possible? What other factors might cause this experience?
<p>
You're not going to like my answer, but "it depends". The height at which the antenna is erected, how tight you pull it between two trees, how you feed it, the type of coax you use, how much power your transmitter uses, how close it is to another object like a fence or a house, what type of ground is below the antenna, what the local noise floor is like, which direction it's oriented, which day you use it and finally, what colour clothes you're wearing at the time.
<p>
That last one isn't strictly true, but it serves to highlight that some differences exist that are so innocuous as to be laughable, for example, have you considered the type of tree and how much foliage there is, when the lawn below the antenna was last watered, etc. My point is that some differences aren't obvious, but they can, and do, make an antenna behave differently.
<p>
In other words, the environment around two identical antennas is hardly ever the same and thus the antenna system as a whole, since the environment and the antenna together combine into a system, are never the same.
<p>
This means that when you go about finding an antenna that's suitable for you, the reviews you read are only part of the story. If the antenna needs ground radials that are physically not possible at your site, then that antenna is unlikely to be suitable for your situation, regardless of the glowing reviews.
<p>
As I said, in my time I've built and bought plenty of antennas. I've also tried several by way of my local amateur radio club. I've operated a mobile station from my car, set-up a portable station in numerous locations using the exact same antenna, and learnt that while the environment is almost never discussed, it has by far the biggest influence on the performance of your antenna.
<p>
My recommendation is to pick an antenna, any antenna, cheap is good, and start. Play with it, change how you erect it, set it up in different locations and I'd highly recommend that you do this with a friend. Between the two of you the shared installation can be used as a baseline to compare your own antenna against and if you're both comparing notes against what you built together, you'll both have a better chance of understanding what particular difference matters in your own setup.
<p>
I'm Onno VK6FLAB
Listen:
Let's talk about reciprosity...
Foundations of Amateur Radio
<p>
All antennas have a radiation pattern that charts on a sphere where it radiates more and where it radiates less than the theoretical isotropic radiator. This comparison is expressed as dBi antenna gain.
<p>
There is a fundamental concept in antenna design called "reciprocity". Essentially it means that transmit and receive behaviour of an antenna is identical. In other words, the radiation pattern of an antenna applies for both transmitting and receiving of signals.
<p>
Unfortunately, this does not mean that if two stations are communicating and one can hear the other, the reverse is also true. Let me explain why.
<p>
Let's set the scene. Imagine two stations, me, VK6FLAB at Lake Monger, in Perth, Western Australia and Charles NK8O in the Lake of the Ozarks state park within the Ozark Mountains in central Missouri. We're both on the 10m HF band and in this story I've finally managed to learn Morse code and I'm "talking" to Charles, mind you, Charles apparently does have a microphone, so perhaps this might actually happen one day.
<p>
To simplify things, we both have the same antenna, the same radio, the same power level, we both love low power or QRP operation, and while we're keeping it simple, we have the same ground conductivity and we're both experiencing the same very low noise levels. While we're constructing this fantasy, the communication paths for both our stations are identical. Note that I said paths, more on that shortly.
<p>
In that situation, both Charles and I have the same experience. We can hear each other at the same level, our S-meter has the same reading, and apart from my current inability to actually use Morse code, our readability is identical. You might think this is "reciprocity", but it's not as simple as that.
<p>
I'm parked near a lake in the middle of a city and often other vehicles come and go. One new arrival has a solar panel on the roof with a noisy inverter and suddenly the local noise in my location jumps from S0 to S6.
<p>
The vehicle arrives whilst I'm transmitting, so at first nothing happens. Charles continues to hear my signal at the same level and at my end I'm blissfully unaware of any change, until I stop transmitting, when I hear the noise. Meanwhile, Charles starts his transmission and I cannot hear him because the local noise in my location is louder than his wanted signal. At this point, Charles still has the ability to hear me, but I can no longer hear him, even though our equipment is identical. The only change is the local noise floor at my location which interferes with my ability to receive the signals coming from Charles.
<p>
This means that I can still send "again, again, local QRM" and I can do so as often as I want. Charles will hear this without any issue, but I won't hear his reply until the local noise stops.
<p>
What this highlights is that two-way communication between two stations involves two signal paths. They might, or might not, follow the same journey through the ionosphere and be between two identical antennas, but the experience for either station can be, and almost always is, completely different.
<p>
Because the ability to transmit isn't affected by local noise at the transmitter, it doesn't figure into the total path loss when you're calculating it for the receiving station. However, when the roles are reversed, it does. So when you're receiving, you need to take into account your local noise, but when you're transmitting, you don't.
<p>
So, when Charles is transmitting to me, I need to take into account my local noise and ignore his, and when I'm transmitting to Charles, he needs to take into account his local noise, but not mine.
<p>
This is how you can have so-called "alligator" stations, all mouth, no ears. The station is likely using high power with a high gain antenna in a noisy environment. This means that everyone can hear them, but because their local noise is so high, they can often only hear other alligators, but not the rest of the world who can perfectly hear them. If you encounter a station on-air that keeps calling CQ, regardless of how many people are calling back, that's an "alligator".
<p>
So, the takeaway is that even if you can hear a station, it doesn't mean that they can hear you and the reverse is also true. You can be transmitting and heard all over the place, but if you're in a high noise environment, you might not be able to hear them. It's one reason that QRP stations prefer to work in low noise environments where they can hear many more stations.
<p>
It reminds me of a funny story told by Wally VK6YS, now SK. In his early amateur radio days he operated from Cockatoo Island, an island off the north coast of Western Australia, near Yampi Sound, which is where his callsign came from. With a new radio and transverter for 6m, Wally had been calling CQ for weeks, but nobody would talk to him. Occasionally he'd hear a faint voice in the background. Meanwhile it transpired that amateurs across Japan were getting upset that he wasn't responding to their 20 and 40 over 9 signal reports. His transmission was getting out just fine, his receiver wasn't working nearly as well. Turns out that during manufacturing, a pin on the back of his transverter hadn't been soldered correctly. Once he fixed that, he worked 150 Japanese stations on the first day and a lifelong love of the 6m band was born.
<p>
In other words, just because someone can hear you, doesn't mean that you can hear them, sometimes it's noise and sometimes its a faulty connector.
<p>
I'm Onno VK6FLAB
Listen:
Let's talk about gain ...
Foundations of Amateur Radio
<p>
After recently talking about noise, today I want to discuss gain, specifically antenna gain. When you say that your antenna has 18 dBi gain, what does that mean?
<p>
This entire discussion starts with an isotropic radiator or antenna. It's often described as the perfect antenna, but rarely is there any description on how that actually works, so I'd like to start there.
<p>
Before we dig in too much, it's worth remembering that an isotropic antenna is a thought experiment, it cannot physically exist, but it's a useful tool for comparing antennas.
<p>
Antennas have a physical size. There's often a direct relationship between the size of the antenna and the frequencies for which it works best. A lower frequency means a longer wavelength and corresponding large antenna to handle that radio frequency. In contrast, an isotropic antenna is infinitesimally small and responds equally well for all frequencies.
<p>
Similarly, unlike an actual antenna, an isotropic antenna is symmetric in all directions, that is, there's no difference between the back or the front, the top or the bottom, the left or the right. You can position an isotropic antenna in any orientation and there's no difference, not just no detectable difference, no actual difference. The radiation pattern is a perfect sphere.
<p>
As I said, the isotropic antenna is an imaginary, let's call it, ideal antenna, that's used as the base reference to measure all antennas against.
<p>
When you use the word gain in relation to an antenna, you're using the unit dBi and in doing so, you're comparing the antenna against this imaginary perfect isotropic antenna.
<p>
When you see that the gain of an antenna is 2.15 dBi, you're saying that this antenna performs better than the isotropic antenna and does so by 2.15 dB.
<p>
There's one "minor" detail missing in that statement.
<p>
The full statement, often completely overlooked, is that this antenna performs better than the isotropic antenna and does so by 2.15 dB, in some directions, but not all.
<p>
Said differently, antenna gain comes from distorting the ideal, perfect sphere into different shapes. For example, the 2.15 dBi gain of a horizontal dipole antenna distorts into a squashed doughnut on its side.
<p>
In other words, there are directions where a dipole radiates better and has an increased gain when compared to an isotropic antenna, but there are also directions where it radiates worse, much worse, if at all. In the case of a dipole, it receives best from the side and worst in line with the antenna and I'll point out that the doughnut is also an idealised shape that in turn gets distorted by proximity to other objects, like the ground.
<p>
Consider that a dipole has 2.15 dBi gain over an isotropic antenna. This means that, for some directions the gain is increased and for some directions it's decreased, perhaps even eliminated. In other words, in some direction, the antenna amplifies the signal and in other directions it attenuates the signal, potentially even to zero at a so-called null in an antenna radiation pattern.
<p>
As I've said before, an antenna receives a combination of both wanted signal and unwanted noise. For an isotropic antenna all signals, from any direction, both wanted and unwanted, are treated the same. This is not true for an antenna that has gain.
<p>
Consider an antenna that exhibits gain in one specific direction and loss in all other directions. If you were to point that antenna at a wanted signal, the incoming signal would be amplified in that direction and attenuated in all other directions. If noise comes from all directions equally, most of the noise would be attenuated and only a little bit of noise coming from the same direction as the wanted signal is amplified.
<p>
Overall, this means that the total amount of incoming noise is reduced in comparison to the wanted signal. In other words, the noise floor is reduced and the signal level is increased, making the signal more audible above the noise.
<p>
This means that the impact of antenna gain is that the Signal to Noise Ratio is improved for an incoming signal in comparison to local noise.
<p>
Notice also, that the antenna gain works in multiple ways. It serves to improve the local signal to noise ratio, by attenuating noise and amplifying a wanted signal, but it also increases the transmitted signal that's sent towards the other station.
<p>
Both affect your station's performance, but do so at different sides of the communication link and because we're talking about two separate signals, an incoming one and an outgoing one, the optimal direction might not be the same for both.
<p>
So, now what do you think the impact might be of adding an 18 dBi Yagi to your station?
<p>
I also have a supplementary question. If a commercial antenna is compared with a dipole, using the dBd unit, is the antenna compared to the entire radiation pattern of a dipole and if so, at what height from what type of ground and is that a useful comparison, or hiding the true performance of such an antenna?
<p>
I'm Onno VK6FLAB
Listen:
Let's talk about noise ...
Foundations of Amateur Radio
<p>
Today I'd like to talk about noise, but before I do, I need to cover some ground. Recently I explored the idea that, on their own, neither antenna, nor coax, made a big difference in the potential for a contact when compared to the impact of path loss between two stations.
<p>
I went on to point out that you'd be unlikely to even notice the difference in normal communications. Only when you're working at the margins, when the signal is barely detectable, would adding a single dB here or there make any potential difference.
<p>
In saying that, I skipped over one detail, noise.
<p>
Noise is by definition an unwanted signal that arrives together with a wanted signal at the receiver. In HF communications, noise comes from many sources, the galaxy, our atmosphere, and man-made noise from things like electrical switches, motors, alternator circuits, inverters and computers.
<p>
The example I used was my 10 dBm beacon being reported by an Antarctic station. My signal report was about 5 dB above the minimum decode level and based on signal path calculations, -129 dBm, or around an S0 signal level. What that statement hides is that this is in the context of a noise level that's lower than -129 dBm. Remember, a negative dBm value means a fraction of a milliwatt.
<p>
While you're considering that, think of the reality of an Antarctic station. This particular station, "Neumayer III" has three 75 kW diesel generators, a 30 kW wind turbine generator, 20 caterpillar trucks, 10 snowmobiles and 2 snow blowers and computers and technology to support 60 people, in other words, plenty of local noise.
<p>
This makes it all the more remarkable that my 10 dBm beacon was heard and that there was an amateur there to set-up the receiver in the first place.
<p>
Before I continue, picture mountain tops peaking through the top of a cloud layer as viewed from the window of an aeroplane. If the cloud layer increases in height, less and less mountain tops are visible, until at some point, only clouds are visible. Alternatively, if the cloud layer descends, more and more of the peaks are visible, until at some point no cloud remains and you see the mountains in all their magnificent glory.
<p>
In that analogy, mountains represent signals and the cloud layer is the equivalent of the noise floor, and in a similar way, signals can be heard or not, depending on the relationship between the level of noise in comparison to the level of the signal. There's a name for this, it's called the signal to noise ratio or SNR, where a value of 0 dB means that noise and signal are at the same level, negative SNR values mean that the signal is weaker than the noise, positive SNR values means that the signal is stronger than the noise. If you know the power level in dBm for both the noise and the signal, you can subtract the two and end up with the signal to noise ratio.
<p>
In reality, all receiving stations have to contend with noise.
<p>
If I arbitrarily set the local noise floor at -100 dBm, somewhere halfway between S4 and S5, I'll mostly get laughed at by many stations, either because it's too high or too low. In case you're wondering, I've worked my station in both S0 noise and S9 noise environments and it's fun trying either and comparing. It's one of the reasons I often use a mobile station, to get away from urban noise around me, and you don't have to go far, a local park might be far enough from local noise to whet your appetite.
<p>
Besides, -100 dBm is a nice round number to play with.
<p>
You might recall that a typical path loss number for a 2,500 km contact on HF on the 10m band is about 129 dB. With a noise floor of -100 dBm, we immediately know how much output power is required to be heard above the noise. If the received signal has to be at least more than -100 dBm and we know that the path loss is 129 dB, then our transmitted signal needs to at least be enough to make up the difference.
<p>
Said differently, if our output power is too low, the signal at the receive station will fall below the noise and they won't be able to hear us.
<p>
So, if we start at say 30 dBm, have a path loss of 129 dB, we'll end up at -99 dBm, which is 1 dB above -100 dBm. Said in another way, the SNR for this is 1 dB.
<p>
I'd like you to notice something.
<p>
I've said nothing about the noise floor at the transmitter. We could have low noise, or horrendous noise, either way, it makes no difference to the receiver. What it hears is entirely dependent on the noise floor at the receiving station.
<p>
I wonder if that observation changes anything about what you think the impact might be of adding an 18 dBi Yagi to your station?
<p>
I'm Onno VK6FLAB
Listen:
How much does your coax and antenna matter?
Foundations of Amateur Radio
<p>
Recently I explained some of the reasons why I've shifted to using dBm to discuss power. You might recall that 1 Watt is defined as 1,000 mW and that's represented by 30 dBm. 10 Watts is 40 dBm, 400 Watts, the maximum power output in Australia is 56 dBm and 1,500 Watts, the maximum in the USA, is just under 62 dBm. My favourite power level, 5 Watts, is 37 dBm.
<p>
I mentioned that using dBm allows us to create a continuous scale between the transmitted power and the received signal. On HF, an S9 report is defined as -73 dBm. Between each S-point lies 6 dB, so an S8 signal is -79 dBm, S7 is -85 dBm and so-on to S0, which is -127 dBm. Said differently, to increase the received signal by one S-point you need to quadruple the power output.
<p>
Now, let's consider a contact with a 100 Watt station, 50 dBm. Let's imagine that the receiver reports an S8 signal. That means that between a transmitter output of 50 dBm and the received signal at -79 dBm, there's a loss of 129 dB. If we dial the power down to 5 Watts, our 37 dBm will be received at -92 dBm, and earn a S6 report, which, in my experience, is pretty common. If we instead use the maximum power permitted in Australia, we'd gain 6 dB and end up at -73 dBm, or S9. The maximum power output permitted in the United States, 62 dBm, is only 6 dB higher and not even enough to get you "10 over 9" at the other end.
<p>
At this point I could say, see, "QRP, when you care to send the very least", and be done with it. While it's true in my not so humble opinion, that's not where I'm going with this.
<p>
That 129 dB of loss is made up of a bunch of things. For example, there's the coax loss at either end, the antenna gain at either end and a big one, the path loss between the two antennas.
<p>
Let's assume for a moment that coax loss and antenna gain cancel each other out. You might think that's nuts, but consider that 100 m of RG58 coax on the 10m band has a loss of around 8 dB and a dipole has an isotropic gain of 2.15 dBi. In case you're not sure what that means, a dipole has a gain of 2.15 dB over the ideal radiator, a theoretical isotropic antenna. Now it's unlikely that you are going to connect a dipole to 100 m of RG58, so let's say a quarter, or 25 m instead. The coax loss is also quartered, or about 2 dB, which pretty much means that your dipole gain and your coax loss essentially cancel each other out.
<p>
So, as a working number, assuming both stations are similar and ignoring SWR mismatch, pre-amplifiers, filters, and all manner of other tweaks in the signal path, 129 dB loss is a good starting point to work with. If you use a free space path loss calculator, that's the equivalent of the loss for a 2,500 km contact on HF on the 10 m band.
<p>
Now, if you were to replace the RG58 with something like RG213 coax, the loss drops from around 2 dB to 0.9 dB, so your signal just increased in strength by 1.1 dB, or not enough to make any difference in this example.
<p>
Of course there's a benefit in using lower loss coax, I mean, 1.1 dB gain isn't nothing, but it really only matters when the conditions are marginal. If you're going to run your coax to the other side of a paddock, you might discover that your signal changes by a whole S-point, but realistically, most of the time you're not going to notice.
<p>
Similarly, and perhaps more importantly, in the scheme of things, your antenna is also just fiddling around the edges when compared to the path loss of 129 dB. For example, if you double your antenna gain, you're only seeing an improvement of half an S-point and most likely you won't actually notice.
<p>
Before you grab the nearest chicken to pluck feathers to come after me with, I'd like to point out that each element on their own has a minimal impact on the total system, but that doesn't mean that improving your station is useless, far from it. If you use quality coax, have an antenna that is performing well, is a good match to your transmitter and coax, use appropriate filters and pre-amplification, you're likely to make more contacts more often, but the bottom line is that you actually need to be on air to make noise and ultimately that's going to represent the biggest improvement in your station performance.
<p>
Case in point, the other day my WSPR or Weak Signal Reporter beacon, with 10 dBm output, was reported 7,808 km away by DP0GVN, the club station of the German Antarctic Research Station "Neumayer III" in Dronning Maud Land, Antarctica, a first for me. WSPR reported that as a signal of -26 dB.
<p>
Previously I proved that when WSPR reports -31 dB, about 75% of decodes are successful. In other words, we can think of my report as being 5 dB above the minimum decode level. This is interesting for several reasons, least of which is that a report of -26 dB doesn't appear to have a relationship to anything else, something which I've observed before.
<p>
Looking further, if we use our notional 129 dB loss figure and start at the beacon power of 10 dBm, we end up at -119 dBm, which is between S1 and S2. In reality, the path loss for that contact is more likely to be in the order of 10 dB worse, making the signal at the receiver -129 dBm or around S0. In those kinds of marginal conditions, where there's 5 dB between being heard and not, finding an extra dB or two in better coax or antenna is absolutely worth the investment, but if you're in a contest making points, you're not going to care. Being on the right band, pointing in the right direction and being on-air making contacts is going to be much more important.
<p>
That said, I'll leave you with a question. Given our obsession with antennas, what might the impact be of adding an 18 dBi Yagi to your station?
<p>
I'm Onno VK6FLAB
Listen:
Gadgets on Demand
Foundations of Amateur Radio
<p>
The other day I went looking for a software defined radio or SDR for HF. This happened because all such devices on my desk are rated at higher frequencies and I've still not managed to fix the broken SMA board connector on the transverter I purchased over a year and a half ago.
<p>
In case you're wondering, the design has two SMA connectors attached at either end of a printed circuit board, also known as a PCB. The board slides into a metal case and both connectors are tightened to either side of the case, which causes the problem when the circuit board is slightly shorter than the case and the nuts pull the connector apart, causing the device to fail.
<p>
Replacing the SMA board connectors would be relatively simple, but they appear hard to come by and the micro SMA connectors that a friend purchased to help, changed the task into finding adaptors, which I've not managed to solve yet.
<p>
I'm detailing this all for a purpose, trust me.
<p>
Anyway, the hunt for an SDR for HF lead me to a project called "Radioberry". It's a design by Johan PA3GSB which is designed to be a so-called "hat" for a Raspberry Pi. Think of it as an expansion card to create functionality, in this case a radio capable of transmitting and receiving on HF, covering 0 to 30 MHz, perfect for my current needs.
<p>
The design uses a Raspberry Pi computer to power and control the board, including programming the on-board FPGA, accessing the actual data and sharing that with the user, either via a touch screen, or using USB, Ethernet, Bluetooth or Wi-Fi. The board itself has two external connectors, one for transmit, one for receive and when you combine it with the Pi, fits neatly into a box which you could 3D print. Amplifier and band filters are left as an exercise to the enterprising amateur, though there is an amplifier design on the github repository. If you're curious, it's based on the work by the Hermes Lite 2 group.
<p>
Johan specifically doesn't sell this device, instead you can choose to buy it from other enterprising individuals, or better still, build your own. Over the last few years I've started noticing several people in the so-called maker community, people, who a lot like radio amateurs, build stuff for fun, using online printed circuit board services.
<p>
If you're unfamiliar with the concept, you can design a schematic, layout a PCB, have it manufactured and optionally even built and sent to you. To get an idea of what this might look like, I picked a random online supplier, uploaded the specifications for a Radioberry and costed the whole thing. Suffice to say that the biggest charge is the $50 set-up fee.
<p>
Any enterprising engineer would have punched the "Buy Now" button and be done with it, but in some things I'm pretty cautious, so I haven't, yet. I don't know enough about the design or schematic to know how it works, to troubleshoot it, to fix any potential issues, or even to know what kinds of issues there might be, even if they're obvious to anyone with electronics experience.
<p>
To make it clear, my electronics experience is rudimentary at best. I'm comfortable with block diagrams, understand the basic principles behind most passive elements, but if you're going to get into trace length and signal timing, I'm not anywhere even remotely qualified to troubleshoot, let alone spot problems. That's not to say that I am stopping before I start, the opposite is true.
<p>
I'm using this as an experience to gently get my feet wet.
<p>
Back to the apparently too detailed explanation of the transverter. Joining the dots you can probably guess where I'm going with this. Given the access to countless documented transverter designs, I feel comfortable enough to work on a design, construct a PCB and have it manufactured. At the rate I'm going, that should get a solution before I can find a PCB edge-mounted SMA connector, well, at least that's my excuse. I'm also eyeing off this same process to build a logging volt meter, since the Internet seems to believe that I should pay hundreds of dollars for a volt meter and an I/O port, even if the chip inside costs all of $6.
<p>
Oh, the transverter I purchased a year and a half ago costs three times as much as having five of them built on demand, so there's that.
<p>
For all my life I've been a firm believer in software. I've also been on a computer driven manufacturing journey for a couple of years, still in the process of commissioning my new toys, much to the merriment of some of my fellow amateurs and the idea that I can have a circuit design built and shipped to my door just makes me tingle with anticipation.
<p>
If you're already ahead of me on this journey, please don't hesitate to point at any potholes on the road and if you're following along, if you break it, you get to keep both parts.
<p>
I'm Onno VK6FLAB
Listen:
All the power in the observable universe expressed in milliwatts ...
Foundations of Amateur Radio
<p>
If you've been following my amateur radio journey, you'll have likely noticed that I've been straying from the fold. The words I use for power have been changing. I've reduced references to Watt and increased use of the term decibel.
<p>
Initially this was incidental, recently it's been more of a deliberate decision and I'd like to explain how this came to be. It starts with representing really big and really small numbers.
<p>
Let's start big.
<p>
On 14 September, 2015 the first direct observation of gravitational waves was made when a pair of black holes with a combined estimated weight of 65 solar masses merged. The signal was named GW150914, combining "Gravitational Wave" and the observation date to immortalise the event.
<p>
Following the collision, it was estimated that the radiated energy from the resulting gravitational waves was 50 times the combined power output of all the light from all the stars in the observable universe. As a number in Watts, that's 36 followed by 48 zeros. If you're curious, there's even a word for that, 36 Quindecillion Watts.
<p>
Now let's look at small. The typical signal strength received from a GPS satellite, like say by your phone, is about 178 attowatts, or in Watts, 0.000 and so on, in all, 13 zeros between the decimal point and then 178.
<p>
What if I told you that the energy associated with the collision of those two black holes could be expressed in comparison with a milliwatt. Remember, this collision emitted more energy than all the output of light from all the stars in the observable universe. The expression for all that power is 526 dBm.
<p>
Similarly, the tiny received GPS signal can be expressed as -127.5 dBm.
<p>
Just let that sink in. All the power in the observable universe through to the minuscule power received by the GPS in your phone, all expressed between 526 dBm and -127.5 dBm, and not a zero in sight.
<p>
As I mentioned, the unit dBm relates to a milliwatt. As a starting point, let me tell you that 1 Watt is 1,000 milliwatts and is represented by 30 dBm.
<p>
The decibel scale doesn't work quite the same as other number ranges you might be used to. Adding the value 3 doubles its size and adding the value 10 increases its size by a factor 10.
<p>
For example, to double power from 1 Watt or 30 dBm, add 3 and get 33 dBm, which is the same as 2 Watts. If you want to increase 1 Watt by a factor 10, again, starting with 30 dBm, add 10 and get 40 dBm which is 10 Watts. Similarly, 50 dBm is 100 Watts and 60 dBm is 1,000 Watts.
<p>
Going the other way, halving power, remove 3. So taking 3 from 60 dBm is 500 Watts or 57 dBm. Dividing power by a factor 10 works the same, take 10. So 47 dBm is 50 Watts and 37 dBm is 5 Watts.
<p>
If you get lost, remember, dBm relates to a milliwatt. 1 Watt is 1,000 milliwatts and is represented by 30 dBm. Divide by a factor 1,000, remove 30 and end up with 0 dBm, which is the same as 1 milliwatt. I'll say that again, 0 dBm is the same as 1 milliwatt.
<p>
It takes a little getting used to, but you can do some nifty things. For example, remove 10 to get a tenth of a milliwatt, or -10 dBm.
<p>
This same process of adding and subtracting applies in other ways too. Attenuation, or making a signal weaker, and amplification, or making a signal stronger can use the same rules.
<p>
For example, if you apply 3 dB of attenuation, you're making the signal 3 dB weaker, or halving it, so you subtract 3 dB from your power output. If your amplifier is rated at 6 dB gain, you're quadrupling the output and you add 6 dB to your power output.
<p>
Similarly, if you talk about the gain of an antenna, you add it. If the gain is 20 dBi, you add it to the power output. You can use this for coax loss calculations as well. A 100m length of RG-58 at 28 MHz has a loss of 8 dB. You can directly subtract this from the power output of the transmitter and know precisely how much power is making it to the antenna.
<p>
There's more. The radio amateur S9 signal strength on HF, something which we consider to be a strong signal, can be expressed as -73 dBm or a very small fraction of a milliwatt. An S8 signal is 6 dB weaker, or -79 dBm. A 20 over 9 report is -53 dBm. I will point out that this is at 50 Ohm.
<p>
As a result, we now have a continuous scale for all the elements in the transmission chain between the transmitter and the receiver.
<p>
While I'm here, I've already mentioned that negative dBm readings relate to fractions of a milliwatt, so values between 0 and 1.
<p>
This highlights one limitation of this scale. We cannot represent 0 Watts. Mind you, that doesn't happen all that often. The thermal noise floor in space at 1 Hz bandwidth, that's at 4 kelvins, is -192.5 dBm, which practically means the minimum level of power we need to express. It's also a good value to remember because if you're doing funky calculations and you end up with a number less than -192.5 dBm, you can pretty much guarantee that you've probably made a boo-boo.
<p>
0 Watts using the dBm scale is represented by negative infinity, or essentially a division by zero error, really not defined, so there's that.
<p>
I'm Onno VK6FLAB
Listen:
Between decibels and milliwatts ...
Foundations of Amateur Radio
<p>
Between decibels and milliwatts ...
<p>
As you might recall, I've been working towards using a cheap $20 RTL-SDR dongle to measure the second and third harmonic of a handheld radio in an attempt to discover how realistic that is as a solution when compared to using professional equipment like a Hewlett Packard 8920A RF Communications Test Set.
<p>
I spent quite some time discussing how to protect the receiver against the transmitter output and described a methodology to calculate just how much attenuation might be needed and what level of power handling. With that information in-hand, for reference, I used two 30 dB attenuators, one capable of handling 10 Watts and one capable of handling 2 Watts. In case you're wondering, it's not the dummy load with variable attenuation that I was discussing recently.
<p>
I ended up using a simple command-line tool, rtl-power, something which I've discussed before. You can use it to measure power output between a set of frequencies. In my case I measured for 5 seconds each, at the base frequency on the 2m band, on the second and on the third harmonic and to be precise, I measured 100 kHz around the frequencies we're looking at.
<p>
This generated a chunk of data, specifically I created just over a thousand power readings every second for 15 seconds. I then put those numbers into a spreadsheet, averaged these and then charted the result. The outcome was a chart with three lines, one for each test frequency range. As you'd expect, the line for the 2m frequency range showed a lovely peak at the centre frequency, similarly, there was a peak for the other two related frequencies.
<p>
The measurement data showed that the power measurement for 146.5 MHz was nearly 7 dB, for 293 MHz it was -44 dB and for 439.5 MHz it was -31 dB. If you've been paying attention, you'll notice that I used dB, not dBm or dBW in those numbers, more on that shortly.
<p>
From a measurement perspective we learnt that the second harmonic is 51 dB below the primary power output and the third harmonic was about 38 dB below the primary power output.
<p>
First observation to make is that these numbers are less than shown on the HP Test Set where those numbers were 60 dB and 62 dB respectively.
<p>
Second observation, potentially more significant, is that pesky dB thing I skipped over earlier.
<p>
If you recall, when someone says dB, they're referring to a ratio of something. When they refer to dBm, they're referring to a ratio in relation to 1 milliwatt. This means that when I say that the power reading was 7 dB, I'm saying that it's a ratio in relation to something, but I haven't specified the relationship. As I said, that's on purpose.
<p>
Let me explain.
<p>
When you use an RTL-SDR dongle to read power levels, you're essentially reading numbers from a chip that is converting voltages to numbers. In this case the chip is an Analog to Digital Converter or an ADC. At no point has any one defined what the number 128 means. It could mean 1 Volt, or it could mean 1 mV, or 14.532 mV, or something completely different. In other words, we don't actually know the absolute value that we're measuring. We can only compare values.
<p>
In this case we can say that when we're measuring on the 2m band we get a range of numbers that represent the voltage measured along those frequencies. When we then measure around the second harmonic, we're doing the same thing, possibly even using the same scale, so we know that if we get 128 back both times we might assume the voltage is the same in both cases, we just don't actually know how much the voltage is. We could say that there's no difference between the two, or 0 dB, but we cannot say how high or low the voltage is.
<p>
This is another way of describing something I've discussed before, calibration.
<p>
So, if I had a tool that could output a specific, known RF power level, and fed that into the receiver and measured, I could determine the relationship between my particular receiver and that particular power level. I could then measure at all three frequencies and determine if the numbers were actually the same for these three frequencies, which is what I've been assuming, but we don't actually know for sure right now.
<p>
So, at this point we need a known RF signal generator. The list of tools is growing. I've already used a NanoVNA to calibrate my attenuators and I've used a HP RF Communications Test Set to compare notes with.
<p>
At this point you might realise that we're not yet able to make any specific observations about using a dongle to make harmonic measurements, but you can make pretty pictures...
<p>
There's a good chance that you're becoming frustrated with this process, but I'd like to point out that at the beginning of this journey I can tell you that I had no idea what the outcome might be and obviously, that's the nature of experimentation.
<p>
If you have some ideas on how to explore further, feel free to get in touch.
<p>
I'm Onno VK6FLAB
Listen:
Wet and Blue adventures with coax ...
Foundations of Amateur Radio
<p>
Over the weekend a friend of mine convinced me to help plant some trees. Mind you, I was told that this was going to be a blue tree painting day. The Blue Tree Project is now a global awareness campaign that paints dead trees blue to spread the message that "it's OK to not be OK", and help break down the stigma that's still largely attached to mental health.
<p>
In the process, I learnt that my physical stamina is not what it once was and my current appetite for bending over and shovelling dirt is, let's call it, muted.
<p>
After the digging and the sausage sizzle under the branches of an actual blue tree, there was some opportunity for playing radio, something I haven't done in much too long. I wasn't sure when I last got into the fresh air to actually listen, but I must confess, the coax cable that I picked up out of my shed had been hanging there for several years.
<p>
The location where we planned to play was in a rural setting, right next to a dam, which surprisingly actually had water in it. The idea was to set-up a vertical antenna with a couple of ground radials, plug in a radio and have a listen. I have to say, after the digging I was really looking forward to this.
<p>
My piece of coax, about 20 meters long, was used to connect the antenna to the radio so we could sit in the shade whilst the antenna stood out in the sun near the dam.
<p>
The antenna, a telescopic one, came with a ground spike and about eight radials and needed to be tuned to some extent, as-in, near-enough is close enough, since we had an antenna tuner with our radio. To achieve the tuning we wanted to connect a NanoVNA to the coax which was the first challenge. The BNC connectors on my coax were pretty dull, likely a combination of poor quality, accumulated dust, humidity and lack of use.
<p>
As an added bonus the centre pin on one end seemed a little bent.
<p>
After working out how to get an SMA adaptor into the connectors we were in business. Connected up between the antenna and the NanoVNA we set out to get things lined up. The SWR on the display, hard to read in the full sun at the best of times, seemed to be a little odd. Not something I could put my finger on, but if you've seen enough SWR plots you know what it's supposed to look like and for some reason it didn't.
<p>
We bravely carried on, connected the radio to the coax and started tuning around. Didn't seem to be a lot of activity on the 20m band. We couldn't hear the local NCDXF beacon which was odd. Also no FT8 activity, also odd.
<p>
If anything, it seemed like there was nothing happening at all.
<p>
Before we continue, I'll point out that this can happen with a big enough burp from the Sun. I hadn't seen any alerts, so I wasn't buying it. We removed my coax, plugged in something much shorter and the bands came alive with all the activity we'd been expecting.
<p>
And then it started to rain.
<p>
Seriously. Finally got out into the world, got radio activity going, had actual signals to tune to and it starts raining. Glynn VK6PAW and I took one look at each other, shook our heads and dashed for the radio to bring it under shelter. I put on my raincoat, and together we disassembled the antenna and the station and went home.
<p>
Clearly, my coax was faulty. Lesson learnt. Test your coax before you go out and you'll have a better outcome.
<p>
About that.
<p>
Today, a week later, I'm sitting on the floor of my shack with the offending coax between my legs, surrounded by adaptors, a NanoVNA, a RigExpert, a dummy load, a short and an open terminator. No matter how I test, no matter what I test, everything is as it should be. I can tell you that the Time Domain Reflectometry shows me that the coax is 25.8m long, useful information, but not really any surprise.
<p>
There's also no significant return loss, unless you head for 1 GHz, but even then it's perfectly respectable, if anything, better than I expected.
<p>
There are no loose connections, nothing rattling, nothing amiss.
<p>
The only thing that I can even begin to think might be the case is that one of the centre pins on one end of the coax is slightly shorter. Combined with "close enough is good enough" when I attached the SMA adaptor in the field, might account for a connection that never got made, since the adaptor wasn't seated deep enough.
<p>
So, I'm not quite ready to cut off the connectors and re-terminate this coax. I'll be taking it into the field again, but I'll make sure that I bring an alternative, just in case. I'm also leaving the SMA adaptors connected to the coax. Future me will thank me.
<p>
Oh, yes, in-case you're wondering, I'm slowly working out how to improve my stamina. That was not fun. If you want to know more about Blue Trees and its message, check out the BlueTreeProject.com.au website and if you ever just want to talk, get in touch.
<p>
I'm Onno VK6FLAB
Listen:
Checking attenuation numbers ...
Foundations of Amateur Radio
<p>
Before we start I should give you fair warning. There are many moving parts in what I'm about to discuss and there's lots of numbers coming. Don't stress too much about the exact numbers. In essence, what I'm attempting is to explore how we can reduce the power output from a transmitter in such a way that it doesn't blow up a receiver whilst making sure that the signal is strong enough that we can actually measure it.
<p>
With that in mind, recently I discussed the idea of adding a series of attenuators to a transmitter to reduce the power output by a known amount so you could connect it to a receiver and use that to measure output power at various frequencies. One hurdle to overcome is the need to handle enough power in order to stop magic smoke from escaping.
<p>
None of my attenuators are capable of handling more than 1 or 2 Watts of power, so I cannot use any of them as the first in line. As it happens, a good friend of mine, Glynn VK6PAW, dropped off a device that allows you to divert most of the power into a dummy load and a small amount into an external connector. In effect creating an inline attenuator capable of handling 50 Watts.
<p>
The label doesn't specify what the attenuation is, so I measured it using a NanoVNA. To make our job a little interesting, it isn't constant. Between 10 kHz and 1 GHz, the attenuation decreases from 70 dB to 10 dB. We want to measure at a base frequency on the 2m band and its second and third harmonic. The attenuation at those frequencies varies by 11 dB, which means we'll need to take that into account.
<p>
So, let's subject our currently imaginary test set-up to some sanity checking. Our receiver is capable of reading sensible numbers between a signal strength of -127 dBm and -67 dBm and we'll need to adjust accordingly.
<p>
If we transmit an actual 20 Watt carrier, that's 43 dBm. With 110 dB of attenuation, we end up at -67 dBm, which is right at the top end of what we think the receiver will handle. If we're using something like 5 Watts, or 37 dBm, we end up at -73 dBm, which is well above the minimum detectable signal. Our best harmonic measurement was around -30 dBm, which means that with 110 dB of attenuation, we end up at -140 dBm, which is 13 dB below what we think we can detect.
<p>
So, at this point you might wonder if this is still worth our while, given that we're playing at the edges and to that I say: "Remind me again why you're here?"
<p>
First we need to attenuate our 20 Watts down to something useful so we don't blow stuff up. Starting with 110 dB attenuation, we can measure our base carrier frequency and its harmonics and learn just how much actual power is coming out of the transmitter. Once we know that, we can adjust our attenuation to ensure that we end up at the maximum level for the receiver and see what we are left with.
<p>
So, let's look at some actual numbers, mind you, we're just looking at calculated numbers, these aren't coming from an actual dongle, yet. Using Glynn's dummy load as the front-end, at 146.5 MHz, the attenuation is about 30 dB. If we look at a previously measured handheld and rounding the numbers, it produced 37 dBm. That's the maximum power coming into our set-up. With 30 dB of attenuation from Glynn's dummy load, that comes down to 7 dBm. We'll need an additional 74 dB of attenuation to bring that down to -67 dBm, in all we'll need 104 dB of attenuation.
<p>
The third harmonic for that radio was measured at -26 dBm. So, with a 104 dB of attenuation that comes out at -130 dBm, which is below the minimum detectable signal supported by our receiver. However, remember that I told you that our dummy load had different attenuation for different frequencies? In our case, the attenuation at 439.5 MHz is only 19 dB, not 30, so in actual fact, we'd expect to see a reading of -119 dBm, which is above the minimum detectable signal level.
<p>
I realise that's a lot of numbers to digest, and they're specific to this particular radio and dummy load, but they tell us that this is possible and that we're potentially going to be able to measure something meaningful using our receiver. I'll also point out that if you're going to do this, it would be a good idea to take notes and prepare what numbers you might expect to see because letting the magic smoke escape might not be one of your desired outcomes.
<p>
Speaking of smoke, what happens if you consider changing the attenuation when you're measuring at another frequency, like say the second or third harmonic and you see a reading close to, or perhaps even below the detectable signal level as we've just discussed. You might be tempted to reduce the attenuation to increase the reading, but you need to remember that the transmitter is still actually transmitting at full power into your set-up, even if you're measuring elsewhere. This is why for some radios you'll see a measurement that states that the harmonics are below a certain value because the equipment used doesn't have enough range to provide an actual number.
<p>
To simplify my life, using a NanoVNA, I created a spreadsheet with 101 data points for the attenuation levels of Glynn's dummy load between 10 kHz and 1 GHz. I charted it and with the help of the in-built trend-line function determined a formula that matched the data.
<p>
I've also skipped over one aspect that needs mentioning and that's determining if the receiver you're using to do this is actually responding in the same way for every frequency. One way you might determine if that's the case is to look at what happens to the signal strength across multiple frequencies using a dummy load as the antenna. One tool, rtl_power might help in that regard.
<p>
Is this going to give you the same quality readings as a professional piece of equipment? Well, do the test and tell me what you learn.
<p>
I'm Onno VK6FLAB
Listen:
How much attenuation is enough?
Foundations of Amateur Radio
<p>
Recently I had the opportunity to use a piece of professional equipment to measure the so-called unwanted or spurious emissions that a transceiver might produce. In describing this I finished off with the idea that you could use a $20 RTL-SDR dongle to do these measurements in your own shack. I did point out that you should use enough attenuation to prevent the white smoke from escaping from your dongle, but it left a question, how much attenuation is enough?
<p>
An RTL-SDR dongle is a USB powered device originally designed to act as a Digital TV and FM radio receiver. It's normally fitted with an antenna plugged into a socket on the side. I'll refer to it more generically as a receiver because much of what we're about to explore is applicable for other devices too.
<p>
Using your transceiver, or transmitter, as a signal source isn't the same as tuning to a broadcast station, unless you move it some distance away, as-in meters or even kilometres away, depending on how much power you're using at the time. Ideally we want to connect the transmitter output directly to the receiver input so, at least theoretically, the RF coming from the transmitter stays within the measuring set-up between the two devices.
<p>
Assuming you have a way to physically connect your transmitter to your receiver we need to work out what power levels are supported by your receiver.
<p>
For an RTL-SDR dongle, this is tricky to discover. I came across several documents that stated that the maximum power level was 10 dBm or 0.01 Watt, but that seemed a little high, since an S9 signal is -73 dBm, so I kept digging and discovered a thoughtful report published in August 2013 by Walter, HB9AJG. It's called "Some Measurements on DVB-T Dongles with E4000 and R820T Tuners".
<p>
There's plenty to learn from that report, but for our purposes today, we're interested in essentially two things, the weakest and strongest signals that the receiver can accommodate. We're obviously interested in the maximum signal, because out of the box our transmitter is likely to be much too strong for the receiver. We're going to need to reduce the power by a known amount using one or more connected RF attenuators.
<p>
At the other end of the scale, the minimum signal is important because if we add too much attenuation, we might end up below the minimum detectable signal level of the receiver.
<p>
Over the entire frequency range of the receivers tested in the report the minimum varies by about 14 dB, so let's pick the highest minimum from the report to get started. That's -127 dBm. What that means is that any signal that's stronger than -127 dBm is probably going to be detectable by the receiver and for some receivers on some frequencies, you might be able to go as low as -141 dBm.
<p>
At the other end of the scale the report shows that the receiver range is about 60 dB, which means that the strongest signal that we can use is -67 dBm before various types of distortion start occurring. For comparison, that's four times the strength of an S9 signal.
<p>
So, if we have a 10 Watt transmitter, or 40 dBm, we need to bring that signal down to a maximum of -67 dBm. In other words we need at least 107 dB of attenuation and if we have a safety margin of two, we'll need 110 dB of attenuation, remember, double power means adding 3 dB.
<p>
So, find 110 dB of attenuation. As it happens, if I connect most of my attenuators together, I could achieve that level of attenuation, but there's one further issue that we'll need to handle and that's power.
<p>
As you might recall, an attenuator has several attributes, the most obvious one is how much attenuation it brings to the party. It's specified in dB. My collection of attenuators range from 1 dB to 30 dB. Another attribute is the connector it comes with, I have both N-type and SMA connectors in my collection, so I'll need some adaptors to connect them together. One less obvious and at the cheap end of the scale, often undocumented, aspect of an attenuator is its ability to handle power. Essentially we're turning an RF signal into heat, so an attenuator needs to be able to dissipate that heat to handle what your transmitter is throwing at it.
<p>
I said that from a safety perspective I'd like to be able to handle 20 Watts of power. Fortunately we don't need all our attenuators to be able to handle 20 Watts, just the first one directly connected to the transmitter. If we were to use a 20 Watt, 30 dB attenuator, the signal through the attenuator is reduced to 0.02 Watts and the next attenuator in line only needs to be able to handle that power level and so-on.
<p>
To get started, find about 110 dB of attenuation, make sure it can handle 20 Watts and you can start playing.
<p>
Before you start keying up your transmitter, how might you handle a range of different transmitters and power levels and can you remove an attenuator when you test on a different frequency?
<p>
On that last point, let me say "No", you cannot remove the attenuator when you're measuring a different frequency.
<p>
I'm Onno VK6FLAB
Listen:
Starting to measure spurious emissions ...
Foundations of Amateur Radio
<p>
At a recent local HAMfest we set-up a table to measure second and third harmonic emissions from any handheld radio that came our way. The process was fun and we learnt lots and in due course we plan to publish a report on our findings.
<p>
When we received a handheld, we would disconnect the antenna, and replace it with a short length of coax and connect it to a spectrum analyser. We would then trigger the Push To Talk, or PTT button and measure several things. We'd record the actual frequency and how many Watts that the transmitter was producing and then record the power level in dBm for the base frequency, double that frequency and triple that frequency. In other words, we'd record the base, second and third harmonics.
<p>
This resulted in a list of numbers. Frequency and power in Watts are obvious, but the three dBm numbers caused confusion for many visitors. The most perplexing appeared to be that we were producing negative dBm numbers, and truth be told, some positive ones as well, we'll get to those in our report.
<p>
How can you have negative power you ask?
<p>
As I've discussed before. A negative dBm number isn't a negative value of power, it's a fraction, so, -30 dBm represents 0.000001 Watts and you'd have to admit that -30 dBm rolls off the tongue just a little easier.
<p>
What we measured and logged was the overall transmitter output and at specific frequencies. As I've discussed previously, if you transmit using any transceiver, you'll produce power at the intended frequency, but there will also be unintended or unwanted transmissions, known as spurious emissions.
<p>
The International Telecommunications Union, or ITU, has standards for such emissions. In Australia the regulator, the ACMA, uses the ITU standard for radio amateurs, but I should point out that this might not be the case where you are. It's entirely possible, and given human diversity, probable even, that there are places where there are more stringent requirements, so bear that in mind.
<p>
I'll state the standard and then explain.
<p>
For frequencies greater than 30 MHz, the spurious emission must not exceed the lesser of 43 + 10 * log (power) or 70 dB.
<p>
That might sound like gobbledegook, so let's explore.
<p>
First thing to notice is that this is for transmissions where the transmitter is tuned to a frequency greater than 30 MHz, there's a separate rule for frequencies less than 30 MHz and the ITU also specifies a range of different limits for special purpose transmitters like broadcast radio and television, space services, and others.
<p>
Second thing is that the spurious emissions are calculated based on total mean output power. This means that your spurious emissions are considered in relation to how much power you're using to transmit and it implies that for some transmitters you can be in compliance at one power level, but not at another, so keep that in mind.
<p>
The phrase "the lesser of", means that from a compliance perspective, there's a point at which power levels no longer determine how much attenuation of spurious emissions is required. You can calculate that point. It's where our formula hits 70 dB, and that is at 500 Watts. In other words, to meet the ITU standard, if you're transmitting with less than 500 Watts, you're subject to the formula and if you're transmitting with more than 500 Watts, you're required to meet the 70 dB standard.
<p>
It means that, at least in Australia, spurious emissions for amateurs are dependent on transmitter power because the maximum permitted power is currently 400 Watts for an amateur holding a so-called Advanced License.
<p>
Now I'll also point out explicitly that the emission standards that the ITU specifies are for generic "radio equipment", which includes amateur radio, but also includes anything else with a transmitter.
<p>
One thing to mention is that spurious emissions aren't limited to the second and third harmonics that we measured, in fact they're not even limited to harmonics. If you're using a particular mode then anything that's transmitted outside the bandwidth of that mode is considered a spurious emission and there are standards for that as well.
<p>
As an aside, it was interesting to me that in many cases amateur radio is treated separately from other radio services, but the ITU considers our community just one of several spectrum users and it's good to remember that the entire universe is playing in the same sandbox, even if only some of it is regulated by the ITU and your local regulator.
<p>
So, let's imagine that you have a handheld radio that has a total mean power output of 5 Watts. When you calculate using the formula, you end up at 50 dB attenuation. In other words, the spurious emissions may not exceed -13 dBm. So, if your radio measures -20 dBm on the second harmonic, it's compliant for that harmonic, but if it measures -10 dBm, it's not. I should also point out that this is for each spurious emission. About half the radios we tested had a second harmonic that was worse than the third harmonic.
<p>
So, what does this mean for your radio? I'd recommend that you start reading and measuring. You'll need to measure the total mean power, and the signal strength at the base frequency and the second and third harmonic. I will mention that surprises might happen. For example, the Yaesu FT-857d radio I use every week to host a net appears to be transmitting with a power level that doesn't match its setting. At 5 Watts, it's only transmitting just over 2 Watts into the antenna, but at the 10 Watt setting, it's pretty much 10 Watts.
<p>
You also don't need a fancy tool like we were using. All these measurements are relative to each other and you could even use a $20 RTL-SDR USB dongle, but before you start transmitting into its antenna port, make sure you have enough attenuation connected between the transmitter and your dongle, otherwise you'll quickly discover the escape velocity of the magic smoke inside.
<p>
I'm Onno VK6FLAB
Listen:
Gathering Data rather than Opinions ...
Foundations of Amateur Radio
<p>
There's nothing quite as satisfying as the click of a well designed piece of equipment. It's something that tickles the brain and done well it makes the hairs stand up on the back of your neck.
<p>
If time was on my side and I wasn't going somewhere else with this, I'd now regale you with research on the phenomenon, I'd explore the community of people building mechanical keyboards and those who restore equipment to their former glory, instead I'm encouraging you to dig whilst I talk about the second and third harmonics. This is about amateur radio after all.
<p>
Over the years there has been a steady stream of commentary around the quality of handheld radios. Some suggest that the cheaper the radio, the worse it is. Given that these kinds of radios are often the very first purchase for an aspiring amateur it would be useful to have a go at exploring this.
<p>
When a radio is designed the aim is for it to transmit exactly where it's intended to and only there. Any transmission that's not where you plan is considered a spurious emission. By carefully designing a circuit, by adding shielding, by filtering and other techniques these spurious emissions can be reduced or eliminated, but this costs money, either in the design stage, or in the cost of materials and manufacturing. It's logical to think that the cheaper the radio, the worse it is, but is it really true that a cheap radio has more spurious emissions than an expensive one?
<p>
To give you an example of a spurious emission, consider an FM transmitter tuned to the 2m amateur band, let's say 146.5 MHz. If you key the radio and all is well, the radio will only transmit at that frequency, but that's not always the case. It turns out that if you were to listen on 293 MHz, you might discover that your radio is also transmitting there. If you're familiar with the amateur radio band plan, you'll know that 293 MHz is not allocated as an amateur frequency, so we're not allowed to transmit there, in fact, in Australia that frequency is reserved for the Australian Department of Defence, and there's an additional exclusion for the Murchison Radio-astronomy Observatory.
<p>
293 MHz isn't a random frequency. It's twice 146.5 MHz and it's called the second harmonic.
<p>
There's more. If you multiply the base frequency by three, you end up at 439.5 MHz, the third harmonic. In Australia, that frequency falls into the amateur allocation as a second use, its primary use is again the Department of Defence.
<p>
These two transmissions are examples of spurious emissions. To be clear, the transmitter is tuned to 146.5 MHz and these unintended extra signals come out of the radio at the same time.
<p>
This is bad for several reasons, legal and otherwise. The first, obvious one, is that you're transmitting out of band, which as an amateur you already have no excuse for, since getting your license requires you to understand that this is strictly not allowed.
<p>
The International Telecommunications Union, or ITU, has specific requirements for what's permitted in the way of spurious emissions from an amateur station.
<p>
Spurious emissions also mean that there is energy being wasted. Instead of the signal only coming out at the intended frequency, some of it is appearing elsewhere, making the 5 Watts you paid for less effective than you hoped for.
<p>
So, what's this got to do with the click I started with?
<p>
Well, thanks to Randall, VK6WR, I have on loan a heavy box with a Cathode Ray Tube or Green CRT screen, lots of buttons and knobs and the ability to measure such spurious emissions. It's marked "HP 8920A RF Communications Test Set". Using this equipment is very satisfying. You switch it on and a fan starts whirring. After a moment you hear a beep, then the screen announces itself, almost as-if there's a PC in there somewhere - turns out that there is and the beep is the Power On Self Test, or POST beep. Originally released in 1992, this magic box can replace 22 instruments for transceiver testing. I started downloading user manuals, oh boy, there's lots to learn. Bringing back lots of memories, it even has a programming language, Instrument BASIC, to control it. Where have you been all my life? Turns out that in 1992 this piece of kit cost as much as my car. Anything for the hobby right?
<p>
At the next HAMfest I'll be using it to measure as many handhelds as I can get my hands on and taking notes. I have no idea how many I'll be able to test, but I'm looking forward to putting some numbers against the repeated claims of quality and price. I can tell you that a couple of weeks ago I got together with Randall and Glynn VK6PAW and spent an enjoyable afternoon testing several radios and there are some surprising results already.
<p>
Perhaps this is something you might attempt at your next community event, gather data, rather than opinions...
<p>
I'm Onno VK6FLAB
Listen:
Jumping into the unknown ...
Foundations of Amateur Radio
<p>
If you walk into your radio shack and switch on a light, the result is instantaneous, one moment it's dark, the next it's not. What if I told you that as immediate as it appears, there is actually a small delay between you closing the circuit and the light coming on. Likely the distance between your switch and your light is less than say 10 meters, so the delay is likely to be less than 33 nanoseconds, not something you'd notice unless you're out to measure it.
<p>
What if your light switch is 3,200 km away? That's the length of the first transatlantic telegraph cable in 1858.
<p>
Let's start with the notion that between the action of closing a switch, or applying a voltage at one end of the cable and it being seen at the other end takes time. If we ignore the wire for a moment, pretending that both ends are separated by vacuum, then the delay between the two ends is just over 10 milliseconds because that's how long it takes travelling at the speed of light. One of the effects of using a cable is that it slows things down. In case you're curious, the so-called Velocity Factor describes by how much. A common Velocity Factor of 66 would slow this down by 66%.
<p>
This means that there is a time when there is voltage at one end and no voltage at the other.
<p>
There are a few other significant and frequency dependent things going on, we'll get to them, but before we go any further, it's important to consider a couple of related issues.
<p>
Ohm's Law, which describes the relationship between voltage, current and resistance in an electrical circuit was first introduced in 1827 by Georg Ohm in his book: "The Galvanic Chain, Mathematically Worked Out". Initially, his work was not well received and his rival, Professor of Physics Georg Friedrich Pohl went so far as to describe it as "an unmistakable failure", convincing the German Minister for Education that "a physicist who professed such heresies was unworthy to teach science."
<p>
Although today Ohm's Law is part and parcel of being an amateur, it wasn't until 1841 that the Royal Society in London recognised the significance of his discovery, awarding the Society's oldest and most prestigious award, the Copley Medal, in recognition for "researches into the laws of electric currents".
<p>
I'll point out that Ohm only received recognition because his work was changing the way people were starting to build electrical engines and word of mouth eventually pressured the Royal Society into the formal recognition he deserved.
<p>
I also mentioned the speed of light in relation to the delay between applying a voltage and it being seen at the other end, but it wasn't until 1862 when James Clerk Maxwell published a series of papers called "On Physical Lines of Force" that light speed was actually derived when he combined electricity and magnetism and proved that light was an electromagnetic wave, and that there were other "invisible" waves, which Heinrich Rudolph Hertz discovered as radio waves in 1888.
<p>
How we understand transmission lines today went through a similar discovery process. Your radio is typically connected to an antenna using a length of coaxial cable, which is a description for the shape the cable has, but the nature of the cable, what it does, is what's known as a transmission line.
<p>
If you looked at the submarine telegraph cable of 1858, you'd recognise it as coaxial cable, but at the time there wasn't much knowledge about conductance, capacitance, resistance and inductance, let alone frequency dependencies. James Clerk Maxwell's equations weren't fully formed until 1865, seven years after the first transatlantic telegraph cable was commissioned and the telegraph equations didn't exist until 1876, 18 years after the first telegram between the UK and the USA.
<p>
In 1854 physicist William Thomson, was asked for his opinion on some experiments by Michael Faraday who had demonstrated that the construction of the transatlantic telegraph cable would limit the rate or bandwidth at which messages could be sent. Today we know William Thomson as the First Lord Kelvin, yes, the one we named the temperature scale after. Mr. Thomson was a prolific scientist from a very young age.
<p>
Over a month, using the analogy with the heat transfer theory of Joseph Fourier, Thomson proposed "The Law of Squares", an initial explanation for why signals sent across undersea cables appeared to be smeared across time, also known as dispersion of the signal, to such an extent that dits and dahs started to overlap, requiring the operator to slow down in order for their message to be readable at the other end and as a result, message speed for the first cable was measured in minutes per word, rather than words per minute.
<p>
Today we know this phenomenon as intersymbol interference.
<p>
It wasn't until 1876 that Oliver Heaviside discovered how to counter this phenomenon using loading coils based on his description of what we now call the Heaviside condition where you can, at least mathematically, create a telegraph cable without dispersion. It was Heaviside's transmission line model that first demonstrated frequency dependencies and this model can be applied to anything from low frequency power lines, audio frequency telephone lines, and radio frequency transmission lines.
<p>
Thomson worked out that, against the general consensus of the day, doubling the line would actually quadruple the delay needed. It turns out that the length of the line was so significant that the second cable laid in 1865, 560 km shorter, outperformed the original cable by almost ten times, even though it was almost identical in construction, providing physical proof of Thomson's work.
<p>
It has been said that the 1858 transatlantic telegraph cable was the scientific equivalent of landing man on the Moon. I'm not sure if that adequately explains just how far into the unknown we jumped. Perhaps if we blindfolded Neil Armstrong whilst he was landing the Eagle...
<p>
I'm Onno VK6FLAB
Listen:
How fast is Morse code?
Foundations of Amateur Radio
<p>
The first official telegram to pass between two continents was a letter of congratulations from Queen Victoria of the United Kingdom to President of the United States James Buchanan on 16 August 1858. The text is captured in the collection of the US Library of Congress. It's a low resolution image of a photo of a wood engraving. Based on me counting the characters, the text from the Queen to the President is about 650 characters. IEEE reports it as 98 words, where my count gives 103 words or 95 words, depending on how you count the address.
<p>
Due to a misunderstanding between the operators at either end of the 3,200 km long cable, the message took 16 hours to transmit and 67 minutes to repeat back. If you use the shortest duration, the effective speed is just over one and a half Words Per Minute or WPM. That's not fast in comparison with speeds we use today. Until 2003, the ITU expected that emergency and meteorological messages should not exceed 16 WPM, that a second class operator could achieve 20 WPM and a first class operator could achieve 25 WPM.
<p>
To put the message speed in context of the era, in 1856, RMS Persia, an iron paddle wheel steamship and at the time, the largest ship in the world, won the so-called "Blue Riband" for the fastest westbound transatlantic voyage between Liverpool and Sandy Hook. The journey took nine days, 16 hours and 16 minutes. Similarly, it wasn't until 1861 that a transcontinental telegraph was established across the United States. In 1841 it took 110 days for the news of the death in office of President William Henry Harrison to reach Los Angeles. Today that distance is covered by a 39 hour drive, a 5 hour flight, and about 12 milliseconds on HF radio.
<p>
So, while the speed of the message might not be anything to write home about today, at the time it was world changing.
<p>
Speed in Morse code is measured in a specific way. Based on International Morse code, which is what I'm using throughout this discussion, if you send the word "PARIS" a dozen times in a minute and the next time starts right on the next minute, you officially sent Morse at 12 WPM.
<p>
Looking inside the message of the word "PARIS", it's made up of a collection of dits and dahs. If a dit is one unit of time, then the letter "a", represented by dit-dah, is six units long when you include the spacing. In total, the word "PARIS", including the space after it, is exactly 50 units long. When you send at 12 WPM, you're effectively sending 600 dit units per minute, or ten units or bits per second, each lasting a tenth of a second.
<p>
Unfortunately, there is not a one-to-one relationship between Morse speed and ASCII, the American Standard Code for Information Interchange, for a number of reasons. Firstly, Morse is made from symbols with varying lengths, where ASCII, the encoding that we really want to compare speeds with, has symbols with a fixed length. You cannot simply count symbols in both and compare their speeds, since communication speed is about what you send, how fast you send it, and how readable it is at the other end.
<p>
Thanks to Aiden, AD8GM, who, inspired by my initial investigation, shared the idea and python code to encode Morse dits, dahs and spacing using a one for a dit, one-one-one for a dah, and zeros for spacing. This means that the letter "e" can be represented by "10" and the letter "t" by "1110".
<p>
You can do this for the standard Morse word "PARIS" and end up with a combination of 50 zeros and ones, or exactly 50 bits. I've been extending the code that Aiden wrote to include other encoding systems. When I have something to show it will be on my GitHub page.
<p>
However, using Aiden's idea, we gain the ability to directly compare sending Morse bits with ASCII bits, since they share the same zero and one encoding. If you use standard binary encoded ASCII, each letter takes up eight bits and the six characters for the word "PARIS", including the space, will take up 48 bits. Given that I just told you that the Morse version of the same message takes up 50 bits, you could now smile and say, see, ASCII is faster - wait, what?
<p>
Yes, if you send the word "PARIS " using 8-bit binary coded ASCII it's two bits shorter than if you use Morse. Job done, roll the press, headline reads: "Morse is four percent slower than binary coded ASCII".
<p>
Not so fast grasshopper.
<p>
If you recall, American Morse code, the one that has Samuel Morse's name written all over it, was replaced by a different code, made by Friedrich Gerke which in turn was modified to become what we now know as International Morse code.
<p>
Ask yourself, why did Gerke change the code? It turns out that one of the biggest issues with getting a message across an undersea cable was decoding the message at the other end. Let me give you an example, using American Morse, consider the encoding of "e", dit, and "o", dit-extra-space-dit and now try sending the word "seed" across a noisy line. Did you convey "seed", or was it "sod". In other words, there is room for ambiguity in the message and when you're talking about commerce, that's never a good basis for coming to a mutually binding agreement.
<p>
It turns out that encoding needs to be more subtle than just creating a sequence of bits.
<p>
Something else to consider, 10 bits per second is another way of saying 10 Hz, as-in, this is not just switching, we're dealing with frequencies and because we're not sending lovely sinusoidal waves, from a signal processing perspective, a very horrible square wave, we're also dealing with harmonics, lots of harmonics, and more of them as we speed things up.
<p>
So, if you send binary coded ASCII and compare it to Morse code, will your message actually arrive?
<p>
I'm Onno VK6FLAB
Listen:
Will the real inventor of Morse code please stand?
Foundations of Amateur Radio
<p>
Morse code is a way for people to send information across long distances. The code we use today, made from dit and dah elements is nothing like the code demonstrated and attributed to Samuel Morse in 1837.
<p>
Over years and with assistance from Professor of Chemistry Leonard Gail and Physicist Joseph Henry, then Professor of Literature, Samuel Morse, and mechanically minded Alfred Vail developed an electrical telegraph system that automatically moved a paper tape and used an electromagnet to pull a stylus into the paper and a spring to retract it, marking the paper with lines. The original system was only intended to transmit numbers, and combined with a dictionary, the operator could decode the message. The telegraph was able to send zig-zag and straight lines, transmitting the message "Successful experiment with telegraph September 4 1837". The system was enhanced to include letters, making it much more versatile. On the 6th of January 1838, across 4.8 km of wire, strung across a barn, the new design with letters and numbers was demonstrated.
<p>
To optimise the enhanced version of the code, Alfred Vail went to his local newspaper in Morristown, New Jersey, to count the movable type he found in the compositor's type-cases, and assigned shorter sequences to the most common letters. You might think that this explains the distribution of the codes we see today, but you'd be wrong.
<p>
The 1838 system used four different element lengths and varied the spacing inside a character. For example, the letter "o" was signified by two dits with a two unit space between them, where today it's represented by three dahs. The letter "p" was signified by five dits, today this represents the number "5", and the code didn't distinguish between "i" and "y", between "g" and "j", and between "s" and "z".
<p>
A decade later and an ocean away in Germany, writer, journalist, and musician Friedrich Gerke created the Hamburg alphabet, based on the work by Vail and Morse, it standardised the length of the elements and spacing into what we use today, the dit and the dah. He changed about half of the characters and also incorporated four special German characters, the umlaut version of A, O and U and the CH sound - pronounced like the sound for the composer "Bach" or the Dutch name "Benschop" - not to be confused with the CH in child, or the CK in clock, or the SH sound in shop. It was different in other ways. For example, the letter "i" and "j" had the same code. The code was optimised to be more robust across undersea telegraph cables. I'll be coming back to that before we're done exploring, but not today. If you want to skip ahead, the term you're looking for is dispersion. Gerke's code was adopted in 1851 across Germany and Austria and it is known as Continental Morse code.
<p>
By the time most of Gerke's code was adopted as the European Standard in 1865 as one of many agreements that mark the founding of the International Telegraph Union in Paris, only four sequences of the original 1838 code remained and only two of those, "e" and "h" were identical. Which means that although the idea that Morse code is based around English is often repeated, at this stage it's nothing more than a myth, which my previous word list and subsequent dictionary letter counts across over fifty languages confirm.
<p>
I'll mention that given Gerke's German heritage, I also made a letter count from a modern German dictionary and one from 1901 and found that the letter distribution in those two are very similar with only the letter "s" and "t" swapped between position four and five in the popularity contest stakes. The German letter Top-5 is "enrts" and the "o" is the 16th most popular letter.
<p>
Speaking of "o", one observation to make is that the new International Morse code contained the letter "o" as dah-dah-dah, it also contained the letter "p" as dit-dah-dah-dit. These two codes come from an 1849 telegraph code designed by physicist, inventor, engineer and astronomer Carl August von Steinheil. There is evidence suggesting that he invented a print telegraph and matching dot script in 1836, based around positive and negative pulses, rather than pulse duration. I'm purposely skipping over earlier telegraph systems built and used by Carl Friedrich Gauss, Wilhelm Edward Weber, and Steinheil, only because we're talking about Morse code, not the telegraph.
<p>
The 1865 ITU standard for International Morse code includes several accented letters, symbols for semi-colon, exclamation mark, chevrons and several control codes and both normal and short forms for numbers which merge all the dahs in any digit into a single dah. Many of these codes are not part of the official standard today.
<p>
I'll point out that over time, experienced telegraph operators learnt to decode dits and dahs based on sound alone, negating the need for paper. This translates directly into how we experience Morse in our hobby today, by tone only.
<p>
There is a much more detailed explanation on how the telegraph evolved in a book by Russel W. Burns called: "Communications: An International History of the Formative Years". Fair warning, there are many claims and counterclaims, including the possibility that someone else entirely, Harrison Gray Dyar, a Chemist, invented an electrochemical telegraph, using chemically treated paper to make marks, dits and dahs, and demonstrated it between 1826 and 1828 near a race track on Long Island.
<p>
I'm mentioning this because Samuel Morse is often attributed as the source of all things telegraphy, but the reality appears to be much more nuanced and, unsurprisingly, there are conflicting accounts depending on the source, including acceptance and repudiation that Alfred Vail was the inventor of what we now call Morse code.
<p>
I'm Onno VK6FLAB
Listen:
Is Morse really built around the most popular letters in English?
Foundations of Amateur Radio
<p>
Thanks to several high profile races we already know that sending Morse is faster than SMS. Recently I started digging into the underpinnings of Morse code to answer the question, "Can you send Morse faster than binary encoded ASCII?" Both ASCII, the American Standard Code for Information Interchange and Morse are techniques to encode information for electronic transmission. One is built for humans, the other for computers.
<p>
To answer the question, which is faster, I set out to investigate. I'm using the 2009 ITU or International Telecommunications Union standard Morse for this.
<p>
Morse is said to be optimised for sending messages in English. In Morse the letter "e", represented by "dit" is the quickest to send, the next is the letter "t", "dah", followed by "i", dit-dit, "a", dit-dah, "n", dah-dit, and "m", dah-dah.
<p>
The underlying idea is that communication speed is increased by making the most common letter the fastest to send and so-on. Using a computer this is simple to test. I counted the letters of almost 400,000 words of my podcast and discovered that "e" is indeed the most common letter, the letter "t" is next, then "a", "o", and "i". Note that I said "letter". The most common character in my podcast is the "space", which in Morse takes seven dits to send.
<p>
Also note that the Morse top-5 is "etian", the letter "o" is 14th on the list in terms of speed. In my podcast it's the fourth most popular letter, mind you, my name is "Onno", so you might think that is skewing the data.
<p>
Not so much.
<p>
If I use the combined works of Shakespeare, and given that it represents an older and less technical use of language, and doesn't feature my name, I figured it might have a different result. The top-5 in his words are "etoai", the letter "o" is the third most popular, and "space" still leads the charge, by nearly 3 times.
<p>
I also had access to a listing of 850 job advertisements, yes, still looking, and the character distribution top-5 is "eotin", the letter "o" is the second most popular letter.
<p>
Because I can, and I'm well, me, I converted the ITU Morse Code standard to text and counted the characters there too. The top-5 letters are "etion", but the full stop is a third more popular than the letter "e", mind you that might be because the people at the ITU still need to learn how to use a computer, seriously, storing documents inside the "Program Files" directory under the ITU_Admin user, what were you thinking? I digress. The "space" is still on top, nearly six times as common as the letter "e".
<p>
As an aside, it's interesting to note that you cannot actually transmit the ITU Morse standard using standard Morse, since the document contains square brackets, a multiplication symbol, asterisks, a copyright symbol, percent signs, em-dashes, and both opening and closing quotation marks, none of which exist as valid symbols.
<p>
Back to Morse. The definition has other peculiarities. For example the open parenthesis takes less time to send than the closing one, but you would think that they are equally common, given that they come in pairs. If you look at numbers, "5" takes the least amount to send, "0" the longest. In my podcast text "0" is a third more common than "1" and "9" is the least common. In Shakespeare, "9" is the most common, "8" the least, and in job listings, "0" and "2" go head-to-head, and both are four times as common as the number "7" which is the least common.
<p>
All this to say that character distribution is clearly not consistent across different texts and Morse is built around more than the popularity of letters of the alphabet. For example, the difference between the left and right parenthesis is a dah at the end. If you know one of the characters, you know the other. The numerical digits follow a logical progression from all dits to all dahs between "0" and "9". In other words, the code appears to be designed with humans in mind.
<p>
There are other idiosyncrasies. Most of the code builds in sequences, but there are gaps. If you visualise Morse as a tree, the letter "e" has two children, both starting with a dit, one followed by another dit, or dit-dit, the letter "i", and the other, followed by a dah, dit-dah, the letter "a". Similarly, the letter "t", a dah, has two children dah-dit, "n" and dah-dah, "m". This sequence can be built for many definitions, but not all. The letter "o", dah-dah-dah, has no direct children. There's no dah-dah-dah-dit or dah-dah-dah-dah sequence in Morse. The letter "u", dit-dit-dah has one child "f", dit-dit-dah-dit, but the combination dit-dit-dah-dah is not valid Morse.
<p>
It's those missing combinations that led me to believe that Morse isn't as efficient as it could be and what originally led me to investigate the underpinnings of this language.
<p>
I think it's fair to conclude at this point that Morse isn't strictly optimised for English, or if it is, a very small subset of the language. It has several eccentricities, not unlike the most popular computer keyboard layout, QWERTY, which wasn't laid out for humans or speed typing, rather the opposite, it was to slow a typist down to prevent keys from getting in each other's way when there was still a mechanical arm punching a letter into a page.
<p>
In other words, Morse code has a history.
<p>
Now I'm off to start throwing some CPU cycles at the real question. Is Morse code faster than binary encoded ASCII?
<p>
I'm Onno VK6FLAB
Listen:
Adventures with Morse Code
Foundations of Amateur Radio
<p>
If you've ever looked at Morse Code, you might be forgiven if you conclude that it appears to be a less than ideal way of getting information from point A to point B. The idea is simple, based on a set of rules, you translate characters, one at a time, into a series of dits and dahs, each spaced apart according to the separation between each element, each character and each word.
<p>
The other day I came across a statement that asserted that you could send Morse faster than binary encoded ASCII letters. If you're not sure what that means, there are many different ways to encode information. In Morse, the letter "e" is the first character, represented by "dit", the letter "t" is the second character, represented by "dah". In ASCII, the American Standard Code for Information Interchange, the letter "e" is the 69th character, represented by 100 0101. The letter "t" is number 84 on the list, represented by 101 0100.
<p>
A couple of things to observe. The order of the characters between Morse and ASCII are not the same. That doesn't really matter, as long as both the sender and receiver agree that they're using the same list. Another thing to notice is that in Morse, letters are encoded using dits and dahs and appropriate spacing. In ASCII, or technically, binary coded ASCII, the letters are encoded using zero and one.
<p>
I'll also mention that there are plenty of other ways to encode information, EBCDIC or Extended Binary Coded Decimal Interchange Code was defined by IBM for its mainframe and mid-range computers. It's still in use today. In EBCDIC, the letter "e" is 133 and the letter "t" is 163. It was based around punched cards to ensure that hole punches were not too close together. It was designed for global use and can, for example, support Chinese, Japanese, Korean and Greek. Another encoding you might have heard of is UTF-16, which supports over a million different characters including all the emojis in use today.
<p>
Before I continue, I must make a detour past the ITU or the International Telecommunications Union. The ITU has a standard, called "Recommendation M.1677-1", approved on the 3rd of October 2009, which defines International Morse code. I'm making that point because I'm going to dig deeper into Morse and it helps if we're talking about the same version of Morse. I have talked about many versions of Morse before, so I'll leave that alone, but I will point out a couple of things.
<p>
The ITU defines 56 unique Morse sequences or characters. The obvious ones are the letters of the alphabet, the digits and several other characters like parentheses, quotes, question mark, full-stop, and comma, including the symbol in the middle of an email address, which it calls the "commercial at symbol" with a footnote telling us that the French General Committee on Terminology approved the term "arobase" in December 2002, but it seems that seven years isn't enough time to convince the ITU to update its own standard, mind you, the rest of the world, well, the English speaking part, calls it "at", the letter "a" with a circle around it, as in my email address, cq@vk6flab.com.
<p>
Another thing to note is that this standard is only available in English, Arabic, Chinese, French and Russian, so I'm not sure what the Spanish, Hindi, Portuguese, Bengali and Japanese communities, who represent a similar population size do for their Morse definitions. It's interesting to note that as part of its commitment to multilingualism, the ITU actually defines six official languages. Specifically, the "Spanish" version of the standard appears to be missing.
<p>
There's other curious things. For example, the standard defines a special character called "accented e", though it doesn't describe which accent, given that there are four variants in French alone, I found at least seven versions and it completely ignores accents on the i, the c, the o, special character combinations like "sz" in German and "ij" in Dutch. This isn't to throw shade on Morse, it's to point out that it's an approximation of a language with odd variations. I'm also going to ignore capitalisation. In Morse there's none and in ASCII, there are definitions for both, capitalised and not.
<p>
In addition to things you write in a message, there's also control codes. The ITU defines six specific Morse control codes. Things like "Understood", "Wait", and "Error". ASCII has those too. The first 31 codes in ASCII are reserved for controls like "linefeed", "carriage return", and "escape".
<p>
There are other oddities. The ITU specifies that the control code "Invitation to transmit" is symbolised by dah-dit-dah. If you're familiar with Morse, you'll know that this is the same as the letter "k". The specification says that multiplication is dah-dit-dit-dah, which is the same as "x". There's also rules on how to signify percentages and fractions using dah-dit-dit-dit-dit-dah, the hyphen, as a separator.
<p>
At this point I haven't even gotten close to exploring efficiency, but my curiosity is in overdrive. Is Morse really optimised for English, or are there other forces at work? I'm already digging.
<p>
I'm Onno VK6FLAB
Listen:
The nature and ownership of information
Foundations of Amateur Radio
<p>
Have you ever made an international contact using amateur radio and used that towards tracking an award like for example the DXCC? If you're not familiar, it's an award for amateurs who make contact with at least 100 "distinct geographic and political entities".
<p>
In 1935 the American Radio Relay League, or ARRL published an article by Clinton B. DeSoto, W1CBD, titled: "How to Count Countries Worked: A New DX Scoring System". In the article he asks: "Are Tasmania and Australia separate countries?"
<p>
In case you're wondering, Tasmania has, at least in legal terms, been part of Australia since Federation in 1901. Not to be confused with New Zealand, a separate country over 4,000 kilometres to the east of Australia, Tasmania is the island at the south eastern tip of Australia. It was previously called the Colony of Tasmania, between 1856 and 1901 and before that it was called Van Diemen's Land between 1642 and 1856. Before then it was inhabited by the palawa people who lived there for about 42,000 years. They eventually became isolated after being cut off from the mainland by the Bass Strait when about 10,000 years ago sea levels rose due to the ice age coming to an end. In the last remaining local Aboriginal language 'palawa kani' it appears to have been called 'lutruwita' (/lu-tru-wee-ta/), but no living speakers of any of the original Tasmanian languages exist. As audio evidence, we have a few barely audible sounds spoken by Fanny Cochrane Smith on a wax record from 1899 on which she sang traditional songs.
<p>
I'm mentioning this to illustrate that DeSoto asking the question: "Are Tasmania and Australia separate countries?" is, in my opinion, fundamentally misguided. More so because of an island, well, rock, Boundary Islet, that's split by a border, one half belonging to Victoria, the other half to Tasmania. Specifically, since 1825, the state of Victoria and the state of Tasmania share a land border thanks to a survey error made in 1801. If you're into Islands on the Air, or IOTA, it's part of the Hogan Island Group which for activation purposes is part of the Furneaux Group, which has IOTA designation OC-195.
<p>
One point to make is that today the DXCC does not mention Tasmania, either as a separate entity, or as a deleted entity. It was removed from the DXCC in 1947.
<p>
The DXCC list is pretty famous in amateur radio circles. It's not the only such list. I already mentioned the IOTA list which contains a list of islands and island groups and their IOTA designation. There's also a list of 40 groups of callsign prefixes called CQ zones, published in CQ magazine, and a list of IARU regions maintained by the International Amateur Radio Union. There's also an ITU zone list, maintained by the International Telecommunications Union.
<p>
Each of these lists are essentially grouped collections with an attached label.
<p>
The list of DXCC entities is copyrighted by the ARRL. If you want to use it for anything other than personal use you need to ask permission. In other words, if you write software that for example tracks amateur radio contacts and you make that software available for others to use, you officially need permission from the ARRL to use it to track a DXCC. If you're an amateur outside of the United States your peak body will need permission from the ARRL to issue any DXCC award.
<p>
The ITU, the International Telecommunications Union is a United Nations specialised agency, part of our global community, owned by all humans. It peppers its content with copyright notices. The same is true for the International Amateur Radio Union, the IARU, the global representative body of all radio amateurs. It too peppers its content with copyright notices, even going so far as to add requirements that "(a)ny copy or portion must include a copyright notice" and that "(i)t is used for informational, non-commercial purposes only".
<p>
Let me ask you a question.
<p>
Can you achieve a DXCC without international cooperation?
<p>
Of course not. If you are an American amateur and want to get an award for contacting 100 distinct geographic and political entities, you can only do so by making contacts outside the United States of America.
<p>
As an Australian however, I have, according to the February 2022 version of the DXCC list, 340 countries to choose from, only one of which is the United States of America, and Alaska isn't part of the United States, apparently.
<p>
It might appear that I'm singling out the ARRL, but that's not true. CQ Communications, Inc. owns the list of CQ Zones, the ITU owns the list of ITU zones, the IARU owns the list of IARU Regions, Islands On The Air Ltd. and the Radio Society of Great Britain own the IOTA list and Clinton B. DeSoto W1CBD became a silent key in 1949, his copyright expired in 1999.
<p>
So, is grouping and labelling things sufficient to actually claim copyright? Can I claim copyright for all countries starting with the letter 'A' and calling it the 'Alpha Amateur Award'? My preliminary list for the 'Alpha Amateur Award' includes Afghanistan, Albania, Algeria, Andorra, Antigua, Argentina, Armenia, Australia, Austria and Azerbaijan and because it's not part of the United States, Alaska. Which reminds me, to encourage amateur radio activity in continents that need more, I'll add Africa and Antarctica. Consider that the 2023 edition of the triple A.
<p>
A bigger question to ask is: "Why should I need permission to use any of these lists?"
<p>
Can I create a public repository on GitHub that has all these lists in a single place, so others could use them without needing to hunt? What if I wanted to reformat and reuse these lists to create an online service to show the relationship between each of these lists for use by all radio amateurs? What if I wanted to charge a subscription fee to pay for the service? What if I wanted to roll out a whole company behind it and pay people to maintain it?
<p>
I'm all for people creating things and receiving credit, but at some point we start to take away from the community instead of giving back to it. Are these lists really owned by the various organisations claiming copyright and requiring written permission for their use, or do they belong to all radio amateurs?
<p>
Oh, the 'Alpha Amateur Award' list is copyleft. Look it up.
<p>
I'm Onno VK6FLAB
Listen:
Asking a professional in the community...
Foundations of Amateur Radio
<p>
In the earlier days of my career I worked in a computing centre at a university surrounded by people with different interests and experiences in computing. There were programmers, hardware engineers, technicians, sales people, administrators, educators, support staff, statisticians and even a librarian.
<p>
There wasn't a lot of socialising or foosball, but every now and then we'd bump into each other in the lunchroom and talk about things that were not work related. During such conversations I learnt that people had all manner of interests outside their work, they were volunteer firefighters, or building their house, or active in the girl guides and any number of other unrelated pursuits and skills.
<p>
That same is true for the people inside the hobby of amateur radio. I've met people who were submariners, tow-truck drivers, accountants, paramedics, radio astronomers, telco and broadcast engineers, doctors, IT people, lots of IT people, and plenty of other professions.
<p>
As you might know, I'm self-employed. I am now acutely aware of mixing business with pleasure because not that long ago, every single time I met another person outside my field I'd get asked about some or other computer problem. Similarly I've witnessed medical professionals being asked about specific and personal medical issues and every time I experienced it or noticed it, a little part of me shied away from either telling people what I did or asking others for professional advice.
<p>
Now before you think that I'm telling you not to talk about computers within earshot of me, that's not at all what this is about. It's about building an awareness that there are people in your community from all kinds of different backgrounds with different experiences, something which I've talked about many times before, but, and here's a new thing, some of those people do not want to give free professional advice, or be dragged kicking and screaming back into their day-job when they're out having fun.
<p>
There's a difference between talking about what a virus is and asking about which computer to buy, a difference between talking about the neurological aspects of mushrooms and asking if someone can help you with deciding which medication to use. There's a difference between talking about radio telescopes and asking to access laboratory measuring equipment.
<p>
If you're unsure where the line is, think of it in this way. If your mate is a plumber, it's one thing asking them what sand in your sink means and another thing entirely to ask them to dig up your backyard.
<p>
I'm not telling you how to live your life, I'm asking you to be considerate of those around you who might have a skill set that you lack and need, whom you've met through the amateur community.
<p>
An example of how you might navigate this process is to ask the person if it's appropriate to ask a specific question and to be prepared for hearing "No". Or you might be surprised and find that they're happy to help, to a point. I'd encourage you to be mindful of that point.
<p>
In case you're wondering, nobody has been stepping on my toes and if you recently asked me a question, you haven't overstepped any lines.
<p>
At this point you might be wondering what this has to do with amateur radio and why I'm talking about it now. The answer lies in the nature and evolution of our community. If you look at us as we were a century ago, like I did extensively when I discussed the evolving nature of the so-called "Amateur's Code", apparently written in 1923 by Lieut.-Commander Paul. M. Segal, you'll know that the community from last century is nothing like the community today.
<p>
I'm sure that you agree that today we're not Gentlemanly, we're not beholden to the ARRL, and we're not all male, to name a few obvious changes and as a result the Amateur's code was updated, many times, to reflect our evolution.
<p>
Those changes came about because people had ideas, had discussions, wrote things down and shared them. That's what this is. A mark on the page saying that I'd like our community to be mindful of the expectations made of the members of the community around us.
<p>
Where are your boundaries and what did you do when someone stepped on them?
<p>
I'm Onno VK6FLAB
Listen:
Planning and making lemonade
Foundations of Amateur Radio
<p>
The other weekend there was an amateur radio contest on. Not surprising if you realise that's true for most weekends. For a change, I knew about this contest before it started, because I missed out a year ago, so I did the smart thing to add it to my diary with an alert a month out.
<p>
In this particular contest there's points to be made by being a so-called roving station, that is, one that moves around during the contest and in the past that's how I've participated and had lots of fun. So the die was cast and a plan was concocted.
<p>
Being a rover meant that I would be outfitting my car with my radio. It's been out of the car for several years, taken out when we had the transmission replaced, and never actually returned. I started making lists of everything I'd need, including learning that you can use a bench top power supply to charge a 12V battery if your trusty charger has let the smoke out. I went hunting for the cable that connects the front of the radio to the back and realised that it was still in the car, so I could cross that off my checklist.
<p>
I decided for the first time that realistically I could log using paper and save myself the heartache of finding a computer with a suitable battery and matching software, especially since I'd be operating with low power so making a gazillion contacts wasn't going to be a problem.
<p>
I went to the shops to get some road food, in my case I like to bring water and oatmeal bars which keep me going through the night. One change was that the contest only ran for 24 hours, leaving less time for sleep.
<p>
I found my portable antenna tuner, plugged everything in, configured the radio for remote tuning, and tested it all on the bench in my shack.
<p>
In further preparation I packed my food, got a headlamp out, spare batteries, a pen and a spare, a ring binder for logging and my wristwatch to keep track of logging times.
<p>
The day before the contest I parked the car in the sun, extracted all the cables from behind the backseat, installed the radio, the battery, the head, the suction mount, the microphone, the speaker, the antenna tuner and antenna mount, and got everything where I wanted it.
<p>
In between rain showers I located the ropes I use to keep the antenna from breaking off the car when I'm driving, set it all up to length after hunting through the garage to find my multi-tap antenna to suit. Strapped that all together to the handhold in the cabin with a Velcro strap and called it a day.
<p>
The next morning I drove to my first activation location, installed the antenna on the 40m band, turned on the radio, tuned it, and called CQ Contest. Made my first contact about six minutes after I started. I was excited. Drove to the next location, made the next contact six minutes later. On a roll I drove to my third spot, where things came unstuck.
<p>
I spent the next two hours getting nothing. I changed both location and band, setting the antenna to 15m and after initially tuning once I couldn't get it to tune again. I spent an hour trying. Given that I wasn't far from home, I went back for a break and to pick up one piece of equipment that I should have packed when I started, my antenna analyser.
<p>
I tested the antenna and for reasons I still don't understand, it was only resonant on 19 MHz, not much good if you're trying to tune somewhere on 21 MHz.
<p>
I moved back to my first spot and changed to the 10m band. Three hours to the minute after my second contact, I made another one, this one outside the state.
<p>
By this time it had been raining steadily for four hours, despite a forecast of little or no rain. The car was stuffy, no way to open the window and stay dry, no contacts, no fun. I asked myself why I was doing this and decided that I'd learnt a valuable lesson and packed up and went home.
<p>
I did go out later in the afternoon to provide some moral support to a friend who had made double the three contacts I'd made, but by dusk we had both had enough.
<p>
My lesson for this week? Test the antenna before you go out and bring your analyser. I must add that I've been contesting for years and I've always packed the analyser but never ever needed it. This time I didn't and Murphy let me know that anything that can happen, will.
<p>
It might sound like a dejected wet cat story, but I learnt a valuable lesson and now I've got another challenge, to discover just why my trusty antenna stopped working. If I do find out I'll let you know.
<p>
What unexpected lessons have you learnt of late?
<p>
I'm Onno VK6FLAB
Listen:
Where is your community and how resilient is it?
Foundations of Amateur Radio
<p>
During the week, prompted by a protest on popular social media site Reddit, I rediscovered that there are other places to spend time. It sounds absurd now, but until then much of my social interaction with the world was via a single online presence. This didn't happen overnight. Over the years more and more of my time was spent on Reddit engaging with other humans around topics of my interest, amateur radio being one of them.
<p>
As you might know, I'm the host of a weekly net, F-troop. It's an on-air radio discussion for new and returning amateurs that's been running since 2011 and you can join in every Saturday for an hour at midnight UTC.
<p>
In addition to the net, there's an online component. It captures items of interest shared during the on-air conversation. It's intended to stop the need to read out web addresses on-air, create a historic record of the things we talk about and allow people who are not yet amateurs to explore the kinds of things that capture our interest.
<p>
Since 2014, F-troop online was a website that I maintained. After the announced demise of the service in 2020 I explored dozens of alternatives and landed on the idea to move to Reddit, which happened in March of 2021.
<p>
At the time of selecting Reddit as the successor to the website, I wanted to create a space where anyone could add content and discuss it, rather than rely on a single individual, me, to update the website every time something was mentioned. During the net these days you'll often hear me ask a person to post that on Reddit.
<p>
This to illustrate, at a small scale, how the F-troop community shares its knowledge with each other and the wider community.
<p>
With the realisation that there are other places to spend time, comes an uneasy feeling about how we build our online communities, and how resilient they really are.
<p>
Before the Internet our amateur radio community talked on-air, or in person at club meetings, or shared their interests in a magazine, or wrote letters. Today we congregate online in many different communities. If one of those fails or loses favour, finding those people elsewhere can be challenging, especially if those communities prefer anonymity.
<p>
For quite some time now I have been thinking about how to build a radio amateur specific online community. The issues to surface, address and overcome are wide and varied. I created a list ... hands up if you're surprised ... I will point out that I'm sure it's incomplete, your additions and comments are welcome.
<p>
Funding is the first item to consider. All of this costs time and money. Amateurs are notorious for their deep pockets and short arms, but they're no different from much of humanity. If this community needs to endure, it needs to be financially sustainable from the outset.
<p>
Authentication and Identity is the next priority. If it's for amateurs, how do you verify and enforce that and what happens if an amateur decides not to renew their callsign, do they stop being an amateur? Should this community be anonymous or not?
<p>
Moderation and Content is next on the list. What types of content are "permitted"? What is the process to regulate and enforce it?
<p>
Is this forum public and accessible via a search engine, or private? Can people who are not yet amateurs benefit from the community and use it to learn?
<p>
How do you set rules of conduct and how do you update them? How do you deal with rule infractions and how do you scale that?
<p>
Who is this for? Is it decentralised across each callsign prefix, across a DXCC entity, or based on some other selection criteria?
<p>
Can you have more than one account, or only one per person, or one per callsign?
<p>
What about machine accounts, like a local beacon, repeater, solar battery, radio link, propagation skimmer or other equipment?
<p>
What about bots and APIs? If that doesn't mean anything, a bot, short for robot, is a piece of software that can do things, like mark content as being Not Safe For Work, or NSFW, or it could enforce rules, or look-up callsigns, or share the latest propagation forecast or check for duplicates, scale an image, convert Morse code, check for malicious links, or anything you might want in an online community. The way a program like a bot, or a mobile client, or a screen reader, or a desktop application talks to the community is using an API, or an Application Programming Interface.
<p>
Incidentally, the protest at Reddit is about starting to charge for access to the API, something which will immediately affect software developers and eventually the entire Reddit community, even if many don't yet realise this.
<p>
What about system backups and availability? How seriously are we taking this community? Is there going to be a Service Level Agreement, or are we going to run it on a best-effort basis? How long is it acceptable for your community to be inaccessible?
<p>
What about content archiving and ageing? Do we keep everything forever, do we have an archive policy? What happens if a topic that's permitted one year isn't permitted a year later?
<p>
And those are just to start the discussion.
<p>
There are plenty of options for places to start building another community, but will they last more than a couple of years, or be subject to the same effects that a Coronal Mass Ejection causes on HF propagation, being wildly random and immensely disruptive?
<p>
At the moment I'm exploring an email list as a place to store our F-troop data and I intend to discuss archiving it in the Digital Library of Amateur Radio and Communications.
<p>
Where is your online community and how resilient is it really?
<p>
I'm Onno VK6FLAB
Listen:
What is our legacy?
Foundations of Amateur Radio
<p>
Our hobby has been around for over a century. The Wireless Institute of Australia, or WIA, is the oldest amateur association on the globe, having just marked 113 years since formation. The American Radio Relay League, or ARRL, is four years younger, founded in 1914.
<p>
I'm mentioning these two associations because they documented their journey through many of the years since foundation. The ARRL has published QST magazine since 1915 and the WIA has published Amateur Radio Magazine since 1933.
<p>
Before the Internet and the Digital Library of Amateur Radio and Communications, magazines like QST and AR Magazine were some ways of documenting and archiving achievements across our community.
<p>
If you find my professional biography online, you'll read: Experienced polyglot IT professional, software developer, trouble shooter, researcher, public speaker, educator, writer and publisher, founder and small business owner, podcaster, and licensed radio amateur.
<p>
It's fair to say that I've done a great many things across the technology arena. I have been writing software since before I was a teenager. At the time we used words like freeware and shareware, we copied lines of BASIC from the pages of the latest computer magazine, or recorded the TV teletext signal to access a programme. I recall typing pages of hexadecimal codes and running the result. Very satisfying to make sprites running across your screen.
<p>
In the decades since, technology has moved on. I've had a front-row seat to see that evolution happen. I've also witnessed one of the victims of the 1980's computer craze, the fundamental obliteration of its history. Much has been lost, either physically by destruction or disposal of boxes of magazines or the deterioration of audio cassette tapes once used to store software. I hold a Guinness World Record of Endurance Computing, set in 1989 during the Hobby Computer Club days, but you'll not find it anywhere other than a copy of the Dutch World Records that might be somewhere in my garage, or not. The twice-daily magazine we published over the three days of the event, Elephant News, was lost to time.
<p>
I'm mentioning this because this loss is not limited to the 1980's, it's happening here, today. As our hobby evolves into the software realm, we need to consider just how that legacy continues beyond our own lifetime. For example, we have lost access to the fundamentals of how exactly HAM DRM works, we've lost the source for VK Contest Logger to name another, and the collected designs by so-called antenna guru L.B. Cebik W4RNL (SK) are scattered around the Internet, but as far as I know, none of it is complete.
<p>
Fortunately we have tools at our disposal to keep our history. As I mentioned, the Digital Library of Amateur Radio and Communications or DLARC is an Internet Archive project to catalogue and store current and historic amateur media. In the 30 weeks since starting in October 2022, it now has 75,000 items and continues to grow under the expert stewardship of Program Manager, Special Collections, Kay, K6KJN.
<p>
The DLARC is not the only tool at our disposal and documentation isn't the only way we share technology in our hobby. More and more of what we do is based around software. We use programs to process signals, to generate and receive different modes, to create logs, to model antennas, to log propagation, and that list grows daily.
<p>
One of the most significant changes in software since my childhood is that of the introduction of Open Source Software in 1998. I've spoken about this several times before and I recently pointed at Not1MM as an example of an Open Source contest logger, but that is not the only project available.
<p>
If you visit GitHub.com and search for "amateur radio", you'll discover over a thousand projects showing a healthy ecosystem of activity from people like Daniel EA4GPZ who shared gr-satellites, a collection of telemetry decoders that support many different amateur satellites.
<p>
You'll find APRSdroid by Georg D01GL, which allows radio amateurs to view and report locations using the APRS network.
<p>
There's an Arduino based rotator interface by Anthony K3NG, an advanced ham radio logger called CQRLOG by Petr OK2CQR, a radio modem by Dan KF7IJB, remoteAudio by Tobias DH1TW, and the list goes on.
<p>
I must also point out that I'm only naming the person behind the repository because as is the whole point of Open Source software, anyone can contribute in different ways. You can make a copy of the source-code and write your own version, a so-called fork, or you can create trouble-tickets to explain a bug or problem, there's ways of contributing fixes and ideas and all of that can be done by anyone anywhere. Many of the projects I've just shared are a combination of years of effort by many different people.
<p>
And that is the point of this conversation. Amateur Radio is a collaborative affair. We learn and share from the experience of others. We document how we built a schematic, or an antenna, or managed to achieve some feat and share that with the rest of the community.
<p>
It's not limited to hobbyist projects either. I purchased my Analog Devices ADALM-Pluto SDR hardware specifically because it was Open Source and came with all manner of tools and code that I could tease apart, improve on and change to my own requirements.
<p>
As we make more and more use of technology in our hobby, we run the risk of repeating the mistakes of the 1980's if we don't start making our efforts public and accessible to the community at large.
<p>
Imagine what our hobby would look like if we stopped sharing our successes and failures.
<p>
So, next time you want to look at some software to use, a calculator to build, or a thing you've learnt, consider what a technology appropriate way to share that might be.
<p>
What tools do you use today and how many of them are Open Source? How much of what you do is accessible to others and what happens if you stop paying for the hosting fees on your website?
<p>
I'm Onno VK6FLAB
Listen:
Accolades in Amateur Radio?
Foundations of Amateur Radio
<p>
Today I'd like to start with saying thank you to the Wireless Institute of Australia for awarding me the Brenda Edmonds Education Award "in recognition of outstanding service in the education of the Amateur Radio Community and advancement of licensees."
<p>
It's an unexpected honour and a thrill that leads me to a question about how we recognise the people around us.
<p>
Over the years I've been a member of around a dozen radio amateur clubs and associations. To my recollection, the only one who has ever said thanks, and in my case, more than once, is the Wireless Institute of Australia.
<p>
What of the other clubs? What about the clubs you're a member of, or the groups you meet-up, either for lunch or on the local repeater? What about when you go out on a field-day and set-up a barbecue?
<p>
I look around me and I see activity that goes back more than a century. It's fair to say that every member of the community benefits from that effort. Memes on social media notwithstanding, there is real labour and toil, love and heartbreak, success and failure all around you.
<p>
What process do you have in place to say thanks?
<p>
Now before you start handing out participation trophies to everyone who turns up, mind you, they did when others didn't, consider what saying thanks might look like in your community?
<p>
It could be a special QSL card, or a certificate sent in the mail that someone could hang on their wall. I'm not advocating for sending out monetary awards or trophies, or other such paraphernalia, I'm just asking you to consider who in your group is worthy of a thank you and what that might look like.
<p>
You should also think about what you're saying thank you about. Is it for output, for the number of laughs, the level of participation, how many new club members were signed up, how many contacts someone made, how much fund raising they achieved, how many radios they fixed or how many nets they hosted, or something else?
<p>
You can think about who in your community might serve as an example to strive for and name the award after them. It might be someone who is active right now, or it might be someone who has attained mythical status in the stories you tell each other around the campfire during an overnight activity.
<p>
No matter what you call it, what it's for, how often you award it, what you present and whom you present it to, consider that it's a formal way of saying thank you, from the group to the individual, from all of you to one person in particular.
<p>
Since starting F-troop, I've now hosted more than 600 weekly nets for new and returning amateurs, a feat which we recently celebrated with a morning breakfast on the local aptly named Wireless Hill, but I couldn't have done it without the local repeater group who maintains the repeater we use. I also couldn't have done it without the countless individuals who join in every week, or who quietly sit on the sidelines making sure that the various nodes scattered around the globe are up and running, or the people who did the catering and logistics for the event.
<p>
Looking back, for me that event represents a missed opportunity to say thank you, something which I intend to do something about in the near future.
<p>
So, ask yourself. When was the last time someone in your community received a thank-you for their contribution?
<p>
I'm Onno VK6FLAB
Listen:
A Linux contest logger ...
Foundations of Amateur Radio
<p>
As you might know I'm in the process of building a cross-platform, open source, contest logger. Right now that project is at the stage where there is a proof of concept that you can use and install as a progressive web app on any web browser. It's intended as a starting point for discussion. Note that this is a long way from the stage where you might want to actually use it for any contest, it's not feature complete and if it breaks you get to keep both parts. It's currently cunningly named "contest-logger". No doubt that will change.
<p>
I'm collecting suggestions for features using the GitHub issue tracker, which you're welcome to contribute to. Behind the scenes, I'm writing the documentation that describes how I want to actually develop and design this application. What kinds of things are important, what will drive the process, all the planning stuff that sets up the project. Of course I'm doing this whilst writing articles, looking for work and dealing with the health-care fun and games associated with being alive.
<p>
While my project is nowhere near finished, truth be told, it really needs to start first, I've come across a different tool written by a fellow amateur Michael K6GTE.
<p>
This tool is written for Linux only in Python and is in Beta release at this point. This means that you can install and run the application and most of the functionality works.
<p>
The application is called Not1MM.
<p>
Here's what Michael has to say about his efforts:
<p>
Not1MM's interface is a blatant ripoff of N1MM. It's NOT N1MM and any problem you have with this software should in no way reflect on their software.
<p>
If you use Windows you should run away from this and use some other program.
<p>
I personally don't. While it may be possible to get N1MM working under Wine, I haven't checked, I'd rather not have to jump through the hoops.
<p>
Currently this exists for my own personal amusement. Something to do in my free time. While I'm not watching TV, Right vs Left political 'News' programs, mind numbing 'Reality' TV etc...
<p>
Michael goes on to say that:
<p>
The current state is "BETA". I've used it for a few contests, and was able to work contacts and submit a cabrillo at the end. I'm not a "Contester". So I'll add contests as/if I work them. I'm only one guy, so if you see a bug let me know. I don't do much of any Data or RTTY operating. This is why you don't see RTTY in the list of working contests. The Lord helps those who burn people at the... I mean who help themselves. Feel free to fill in that hole with a pull request.
<p>
You can find Not1MM on Michael's GitHub repository ready for your testing and experimentation. It's also available as a PyPi package if you're already familiar with Python.
<p>
In my opinion, one thing that this tool does well is consider how contest logging can be customised for individual contests and likely it will serve as inspiration for how I intend to implement the plugins in my own project.
<p>
I've also submitted a patch to Not1MM so you can use Docker to install it on your own machine or at least see what the requirements are to make it run in your environment.
<p>
I'm thrilled to have discovered this tool and hope that it solves some of your contest logging issues on your Linux workstation.
<p>
What features are you hanging out for in your contest logging adventures? Feel free to share your bug reports and feature requests to either Michael's project, or mine, or both.
<p>
I'm Onno VK6FLAB
Listen:
Considering the language of our community ...
Foundations of Amateur Radio
<p>
A curious thing happens when you become part of the amateur community, you start to talk like an amateur. This phenomenon isn't specific to being a radio amateur, it happens whenever you join any community. Lead by example, one word at a time, you start to inherit a vocabulary that represents that community. Amateur radio, rife with acronyms and so-called Q-Codes, a standardised set of three-letter codes that start with the letter "Q", does this in spades.
<p>
If you've been around amateurs for more than 30 seconds, it's likely that you have already heard QSL, QTH and QRM, colloquially short for "Yup", "Home" and "Noise". There's an official meaning if you're keen. You can use the three letters as both a question and an answer, so QSL can mean "Can you acknowledge receipt?" and "I am acknowledging receipt."
<p>
Similarly, QTH means "What is your position in latitude and longitude (or according to any other indication)?" and QRM means "Is my transmission being interfered with?"
<p>
In those cases, used either with Morse code or Voice, they can make getting the message across simpler, faster, and more accurate, all important aspects of communication. It's easier to get QTH across to an amateur who doesn't speak English as their first language than it is to ask the whole question.
<p>
Other letter groups also creep into common language of an amateur. You've likely heard the letters: "XYL", but if you haven't, let me explain. Given that amateur radio is an activity dominated by men, "YL" refers to Young Lady and "XYL", refers to eX-Young Lady, a less than complimentary way of referring to one's wife.
<p>
I'd like to point out something curious.
<p>
In Morse code, XYL is sent using: -..- -.-- .-..
<p>
It's intended to represent the word WIFE which is sent in Morse code as: .-- .. ..-. .
<p>
Now, if you know anything about Morse, you'll know that a dit is one unit, a dah is three. Individual elements are spaced by one unit. The space between letters is three units and the space between words is seven units.
<p>
Armed with that knowledge, XYL takes 39 units and WIFE takes 31 units to send.
<p>
So, sending the shortcut actually takes longer and it's clear that this choice is not about efficiency. Describing someone as an eX-Young Lady to refer to your Significant Other seems very 1950's to me. In the situation where you are the female amateur operator, the apparently appropriate way to refer to your Significant Other is as Old Man or "OM". Are female operators supposed to refer to themselves as YL or XYL? Really?
<p>
Sexism aside, this is extremely offensive in a same-sex and gender fluid community.
<p>
Then there's the symbol "88", apparently meant to refer to "Hugs and Kisses", not something I'd feel comfortable sending to anyone other than my partner who is emphatically not an amateur, let alone the idea that it would be appropriate to send it to any random station or the connotations around males sending such a message to a random female operator.
<p>
So, given that we now live in the 21st century and we're no longer in 1950, perhaps it's time to consider what language we teach new amateurs.
<p>
One proposal by Chris M0YNG is to refer to the Operator as "OP" and the Significant Other as "SO". Seems like a good start.
<p>
I will point out that this conversation was brought to my attention by Andreas DJ3EI who was participating in a Mastodon.radio conversation with Tim N7KOM who started the thread.
<p>
I think it's a worthwhile thing to discuss such an evolution of our language, it goes to the heart of our community, you are what you say you are, and words matter.
<p>
So, what words, acronyms and symbols do you use in your amateur community and what are you teaching new amateurs?
<p>
I'm Onno VK6FLAB
Listen:
Measuring the Solar Flux Index at home ...
Foundations of Amateur Radio
<p>
Recently the Australian Space Weather Forecasting Centre issued an alert for a Coronal Mass Ejection or CME expected to impact Earth within 24 to 36 hours. This was presented within the context of seeing the resulting Aurora, but as a user of the HF radio spectrum, I'm subscribed to their email list, not for the pretty pictures, though I would be delighted to actually see them with my mark one eyeball, I'm on the list for the impact on propagation for my hobby.
<p>
As a good citizen I shared the alert with my community both via email and social media and as a result I received some questions and comments. One question was, "What does this mean?", one comment was "it's not going to impact the United States."
<p>
My response was to point out that HF propagation and the impact of the Sun is a very deep rabbit hole and encouraged further research by supplying several links, including a very detailed video by Rohde and Schwarz titled "Understanding HF Propagation", very, highly, recommended.
<p>
Whilst watching that video I discovered that the Solar Flux Index is measured using a receiver tuned to 2800 MHz or 2.8 GHz. Being in the business of having receivers scattered around my shack, I asked myself if I had something that was able to receive on that frequency. My RTL-SDR dongle doesn't cut it without extra hardware, it tops out at 1.75 GHz. However, my PlutoSDR has a standard frequency range that goes up to 3.8 GHz out - of the box - and with some tweaks can make it to 6 GHz, so well and truly within range.
<p>
Now, before I move on, I should mention that an RTL-SDR is a cheap, as-in $20, USB computer accessory that looks like a thumb-drive and is ostensibly built to receive digital television, or DVB-T signals. I've spoken about this previously. It can be used to receive radio frequencies outside the purpose it was built for. The PlutoSDR, or to give its official name the ADALM-PLUTO, on the other hand, something which I've also spoken about, is a single board Linux computer made by some smart people at Analog Devices, specifically for the purposes of learning and experimentation with receiving and transmitting RF. It comes with all manner of documentation and software and to be honest, I'm a little bit in love with mine.
<p>
Back to measuring stuff. In this case I'm attempting to measure the power levels of radio frequencies at 2.8 GHz. I know of a simple tool called rtl_power that can measure RF power over time and started investigating if that tool had been hacked to be able to use the PlutoSDR, rather than the RTL-SDR dongle. It might have been, but I've not yet discovered it, however, that in turn led me to several other tools, most of which I'm still investigating.
<p>
What it does tell me is that I'm not the first person to tread these paths, much has happened and been documented in the analogue sphere, some has been done using digital I/Q data and a transverter, a device that can multiply radio frequencies to make them appear in a different part of the radio spectrum, but I'm not yet sure if anyone has made a Solar Flux Index device out of a PlutoSDR.
<p>
I recalled a wonderful little tool that I've also talked about before, there's a theme here, I'm sure, but the tool, "csdr", written by Andras HA7ILM, which allows you to do all manner of interesting things to a stream of raw data, specifically RF raw data. It has a function called logpower_cf which Andras describes as "useful for drawing power spectrum graphs", which is precisely what I'm looking for.
<p>
Armed with that I'm now in the process of building a compiled version using Docker, so I can run csdr on my PlutoSDR and perhaps generate a power spectrum graph for 2.8 GHz. Of course that will now require that I learn how to extract raw data, known as I/Q data from the PlutoSDR command-line, process it through the logpower_cf function, output an image and hopefully show the result as a web-page. At the moment I'm still in the weeds with a Makefile, but that's not unusual.
<p>
Needless to say that I'm working on it and the result will no doubt turn up on my github page when it's done. In the most innocent terms possible, how hard can it be?
<p>
One takeaway that really needs to be expressed out loud, even if I've hinted at it. All the bits I've talked about here are things I've already been playing with. It wasn't until I came across a salient piece of information about the Solar Flux Index and how it was measured that all the puzzle pieces came together, the PlutoSDR, csdr, rtl-power, logpower_cf, the SFI and a web-server, that I could even imagine this happening.
<p>
The point being that even if you have all of the puzzle pieces in your hands, it might still take one missing piece of information for your brain to go "Ah-ha, wow, yes, this makes sense, I can do this."
<p>
So, keep collecting puzzle pieces, relevant to your own interests and one day you too will get to this point.
<p>
I'm Onno VK6FLAB
Listen:
Propagation during the 2023 Solar Eclipse
Foundations of Amateur Radio
<p>
On Thursday the 20th of April, 2023 at 04:17:56 UTC the world was subjected to a rare event, a hybrid solar eclipse. In Perth I experienced a partial eclipse and people lucky enough to be directly in line, places like Ningaloo Reef, Exmouth and Barrow Island, experienced a total eclipse. Timor-Leste had the experience of the peak total eclipse.
<p>
At the time I went into my shack and refreshed the WSPR or Weak Signal Propagation Reporter beacon map I have open and noticed that my beacon wasn't reported. I sagely nodded my head, that makes sense, no Sun, no propagation and I got on with my life.
<p>
Last week a fellow amateur, Will VK6UU, asked if anyone had any VK6 specific HF propagation reports to make. Being the data geek that I am, I thought to myself, "Aha! I can do some data analytics on the WSPR dataset that I have." So, the die was cast for a few enjoyable hours of importing 2.4 gigabytes of compressed data into a database and constructing a set of SQL queries to see what I could learn.
<p>
Before getting stuck in, I spent a few hours thinking about the problem. How could I go about doing this? Propagation information is notoriously fickle. You have to consider the obvious things like the Solar Index and the Geomagnetic Index which vary considerably. Then there's the nature of the various reports themselves. Not everyone has their beacon on all the time, not everyone has their receiver on all the time. Weekends are more popular than weekdays and popularity overall is growing exponentially. The solar cycle is on the way to its peak, so there's that variation to consider and if that's not enough, how should you compare the Signal To Noise ratio between weak and strong beacons?
<p>
With all that in hand I set about constructing a plan. I created a folder to hold my charts and SQL queries, intent on uploading that to GitHub when the work was done.
<p>
For my very first test I thought I'd count the number of reports per band in a 24 hour window around the eclipse. I imported all the WSPR records that had a VK6 callsign, either as the transmitter or the receiver, given that I was interested in learning if stations transmitting from VK6 could be heard elsewhere and inversely, could VK6 stations hear any other stations?
<p>
As my first effort, I created a scatter-plot to get a sense of what kind of numbers I was looking at. The initial result was interesting. Around the eclipse itself there was no propagation. This wasn't unexpected, since that's what I'd seen on the day at the time on my own map. I changed my data to use a cumulative count per band to see if any band was particularly different and then discovered that there was no propagation at all, on any band.
<p>
That seemed ... odd.
<p>
So, I had a look at the source data and discovered a gap, which accounted for what my chart was showing. I added a fake record for the eclipse time itself, just so I could see where on the chart this gap was. Turns out that for VK6 stations, the gap is just over five hours, but it's not centred around the eclipse. There's a four hour window before the eclipse and a one hour window after it.
<p>
Then I started looking at all the reports from across the world. To give you a sense of scale, across April 2023 the dataset has nearly 139 million rows. It's 12 gigabytes in size. By contrast, in March of 2008 when the first reports started, there were just over 93 thousand reports in a 7 megabyte file. Charting this shows exponential growth, hitting a million reports in July of 2009, 10 million reports in January 2016 and 100 million reports in October of 2021.
<p>
So, the eclipse and global propagation. The results came in and the reports are that there was no propagation, on any band at any point during the just under two hours and 12 minutes before the eclipse and the 38 minutes following it.
<p>
That ... or the WSPRnet.org database was down during the eclipse.
<p>
So, unfortunately I cannot tell you what propagation was like during the eclipse, since it appears that those records don't exist.
<p>
Looks like we'll have to wait until 2031 when we can try this again. We'll all be a little older and wiser by that time and perhaps we can come up with a way to ensure that the global central WSPR data server is running without downtime, scaled to match the growing requirements and paid for by a benevolent organisation with deep pockets.
<p>
I did start considering making lemonade from my lemons and charting the kinds of down time the WSPR server has, but just looking over the various discussion groups showed that this is going to be painful. On the plus side, I learnt about SUM OVER and LAG functions in SQL, so there's that.
<p>
I must confess that if we're going to seriously use WSPR as a propagation analysis tool we need to fix these kinds of issues. I have no doubt that running WSPRnet.org is a massive enterprise and that it costs real time and money to make that happen.
<p>
So, who's up for the challenge and will the real owner of WSPRnet.org please raise their hand?
<p>
Finally, if by chance you were running a WSPR receiver during the 2023 Solar eclipse you might want to consider looking at sharing your logs, since they're potentially the only record still remaining.
<p>
I'm Onno VK6FLAB
Listen:
Doing the same thing over and over again ...
Foundations of Amateur Radio
<p>
Over the years I've used the phrase, which I shamelessly stole, that amateur radio is a thousand hobbies in one. I've discussed countless different activities and adventures that all fall under the banner of amateur radio, in one way or another.
<p>
Since becoming a licensed radio amateur I've had the opportunity to speak with many different amateurs and hear their views on what amateur radio means to them. Based on their responses I've often found myself exploring new aspects of the hobby and discovering new and interesting ways to participate in this community.
<p>
Recently I put together a list of projects that are currently underway in my shack. I discovered that over time this list has evolved from physical radio activities, like portable activations, building antennas, camping, and going to HAMfests, the amateur radio version of a swap meet, into more computer related things like data analytics, writing software, fixing bugs and learning how the insides of a Software Defined Radio works.
<p>
That's not to say that I've given up on camping, or any of the other things, just that my priorities have shifted over time as I discover over and over again, just how big this hobby really is.
<p>
I mention this because one of the recurring observations I encounter is that others are doing the same thing day in and day out. That in and of itself isn't an issue, it's that they begin to describe that they're bored, that they've lost interest, that the hobby is in stagnation, that there's nothing new, that they're frustrated with their progress towards whatever goal they've set themselves.
<p>
For me, the key motivator in this hobby is learning. Everything else follows from there. That might not be your thing. You might be here for the emergency service aspect, or the hill climbing, the soldering and electronics.
<p>
It really doesn't matter why you're here at all. What keeps it fresh is trying new things. For example, if you're here for emergencies, have you set up a disaster event simulation in your community, or attempted to set-up your station 100 km from home and make contacts, using just the very basics?
<p>
If you're into soldering and electronics, have you ever designed your own circuit board, had it manufactured, or even manufactured it yourself, built the project and tested it? What about documenting it and making it available as a project for someone else?
<p>
If you've climbed all the hills in your state, have you tried doing this across the border, or overseas? What about testing with different antennas, or modes, power levels or logging tools?
<p>
The point being that it's easy to keep doing the same thing. What's harder, but potentially more rewarding, is to try something new and experience what happens.
<p>
One thing to keep in mind is that things will go wrong. That's where all the learning happens, so keep at it.
<p>
So, are you doing the same thing over and over again and expecting a different outcome, or are you excited like a newborn puppy, wagging your tail ready for the next adventure?
<p>
I'm Onno VK6FLAB
Listen:
Why is radio regulated?
Foundations of Amateur Radio
<p>
One of the more perplexing things is the nature of radio regulation. If you're a licensed radio amateur, you'll be familiar with this idea, but if you're not it's bewildering and apparently absurd.
<p>
To explain, let me start with a light bulb that your neighbour put on their back porch. It's bright. It's pointing at your house. Like the apparent radiation from a gazillion suns it lights up the bedroom and sleep is hard to come by. Pretty annoying right?
<p>
As it happens, radio is a lot like that. If you know physics, it's exactly like that, but I'll ignore that for today.
<p>
In our modern world we have many different radios that each rely on a specific, let's call it colour, of light. In radio terms this is known as frequencies or radio bands and the entire collection is known as the radio spectrum. You've likely seen this without knowing. Your 2.4 GHz WiFi has an in-built frequency, 2.4 GHz, as does your 5 GHz WiFi. Your FM radio in the car has frequencies as well, 97.7 on the dial indicates 97.7 MHz. If you have an AM radio, 720 AM refers to 720 kHz.
<p>
Hidden in plain sight is why radio is regulated. Those numbers, 5 GHz, 2.4 GHz, 97.7 MHz and 720 kHz are all radio frequencies, or as I suggested, colours. Now imagine turning on a really bright light in the middle of that. All of a sudden your WiFi, FM and AM are wiped out.
<p>
It doesn't stop there. As I said, there are many different radios, and sources of radio frequencies.
<p>
Radio transmissions come from your mobile phone, Bluetooth headset, microwave oven, computer, television, remote control, key-less fob, power supply, car, power meter, solar panel, battery charger, LED light bulb, and the list goes on. Essentially anything electronic has a radio component. Some of these are transmitting unintentionally, like an electric motor or a switch mode power supply. Other things are transmitting on purpose, your microwave oven, your Bluetooth headset and your mobile phone.
<p>
As I mentioned, they're all sharing the same resource, the radio spectrum.
<p>
At this point you might ask about the impact of a single transmitter among all that.
<p>
Well, there are a few phenomena that you should know about.
<p>
Radio waves don't stop. They keep going. There's no boundary. To illustrate that, I have a tiny beacon, a transmitter, that every two minutes sends out a signal that shows my amateur callsign and location. It uses 10 milliwatts. To give you a sense of scale. A typical incandescent light bulb is about 60 Watts. My transmitter uses sixty thousand times less power. It has been heard 13,455 km away, about a third of the way around the planet. I will point out that different frequencies can be absorbed differently depending on how they're used, but you cannot rely on the idea that any radio frequency stops anywhere.
<p>
Another phenomenon is a thing called harmonics. Radio waves not only share the same space or spectrum, they're related to each other. Unless you take very specific precautions, a transmission made at 100 MHz, will be heard at 200 MHz, 300 MHz, 400 MHz, 500 MHz and so-on. While each of those transmissions gets progressively weaker, they still exist. Now imagine that someone else is using one of those other frequencies to communicate emergency information. It's like their backyard just got hit with a bright light.
<p>
To give you a specific example of why this can matter. Consider a radio amateur who uses 7 MHz. This is a licensed amateur radio frequency. Unless that amateur takes specific precautions, the 16th harmonic for 7 MHz is 112 MHz. If that doesn't mean anything to you, it's in the middle of the so-called air-band, frequencies used by aircraft around the planet to talk to each other and the ground. Very bad things could happen if safeguards weren't made.
<p>
As a result, radio is highly controlled and regulated. I'm not going into the laws or legalese here, given that this is a global phenomenon and the rules in their specifics are different in each country. There's a whole hierarchy of regulation, arrived at by international cooperation and agreement.
<p>
These regulations are not identical in each country, far from it. Each country has their interpretation of the rules and balances those with its own use of radio. For example WiFi, a very popular use of the radio spectrum, can be bamboozling in the endless variation of something so seemingly simple.
<p>
Most of this is invisible to most people. You go to the store and buy a WiFi base station and you go on your way. With the advent of online shopping, you can click "buy" on any window, regardless of which country the device comes from. If you're not careful your shiny new device, imported from somewhere is actually illegal in your country and fines and punishment can be severe.
<p>
If you start digging into this, you'll come across rules that for example say that you cannot change the antenna on a particular device. This is because the transmission power of the hardware is strictly regulated so it doesn't interfere with other users. Changing an antenna has the potential to change a number of aspects of your device. It can potentially amplify harmonics that were suppressed by the existing antenna. It could increase the perceived power level and overload other receivers. On a shared frequency it might lock out other users. This is why for example across the European Union, Private Mobile Radio on 446 MHz, or PMR446, a unlicensed radio provision that allows for business and personal use, has heavily regulated hardware. These devices are not permitted in places like Australia, the USA and Canada because in those countries, 446 MHz is used by radio amateurs and military radar systems.
<p>
This is why you'll find equipment like mobile phone amplifiers and jammers are heavily regulated and controlled. You'll also discover that transmitting on public frequencies like the FM broadcast band is a massive No-No. I'm not going into the so-called "FM capture effect", but the impact is that your personal transmitter needs to be locally louder than the station you're trying to break into and that in turn means that your little transmitter isn't so little any longer and the neighbours and the regulator will notice and come looking for you.
<p>
Before this begins to sound like I'm stopping anyone from experimenting, let me point out that licensed radio amateurs have been granted permission to experiment in this magical radio play ground. Of course there are very strict rules around this, but perhaps now there is an understanding on why that might be the case.
<p>
The more you dig in, the more stuff there is to explore and learn. As a radio amateur you are granted the keys to the city as it were.
<p>
If this information was shared with you after you asked a simple question, perhaps it's time to stop what you're doing, consider the impact on your wallet and equipment and in some cases freedom, and instead explore the idea of becoming a radio amateur where you can legally play with this stuff.
<p>
If you're already licensed, perhaps this will help to explain to others why.
<p>
I'm Onno VK6FLAB
Listen:
The antenna system
Foundations of Amateur Radio
<p>
Several years ago I participated in a local contest. Over a 24 hour period I activated my mobile station in about 30 different locations. On my car, my vertical antenna screwed into a boot-lip mount connected to an antenna tuner or ATU, and my radio. I used rope to guy the antenna, threaded through the rear windows and held tight by closing the car boot.
<p>
Setting up consisted of parking the car, triggering the ATU to tune the antenna system and calling CQ. Moving to the next location consisted of driving there and setting up again.
<p>
Although this worked really well, I'm skipping over what I'm interested in exploring today.
<p>
The phrase "triggering the ATU to tune the antenna system" hides a lot of complexity. It was a surprise to me that there were several locations where the ATU just wouldn't tune. Despite my best efforts I was unable to get the system to a point where the radio was happy. In some cases I tuned off frequency and put up with a poor SWR. In others I physically had to move the car and park somewhere else.
<p>
In every case it was completely unknown if a particular location was going to be a problem. I recall for example parking in an empty nondescript car-park and having to drive around to find a location where my set-up would work. Afterwards I considered that the car-park was potentially built on top of an iron ore deposit, an old industrial area, or a pipe-line, all of which were a good possibility.
<p>
The point of this is that an antenna doesn't exist in isolation, it's called a system for a reason. We talk about the theoretical isotropic antenna and add disclaimers about that it cannot physically exist because it's infinitely small. One often overlooked aspect of an isotropic antenna is that it's in free space.
<p>
Free space is defined as space that contains no electromagnetic or gravitational fields and used as a reference. It's a theoretical place. On Earth there is no such thing, there's a planet under your feet, but even in outer space there are both gravitational and electromagnetic fields that impact on an antenna and its performance.
<p>
Staying nearer to home, recently we had a discussion about how close two antennas can be together. A suggested rule of thumb was that they need to be at least one banana or 30 cm away from each other.
<p>
Similarly when we erect a dipole, there's recommendations around needing to have it mounted more than half a wavelength over the ground. Some sources say higher. I'll ask the first obvious question. Is that dipole completely straight? In other words, should the centre be half a wavelength above the ground, or should the ends, and how far should the ends be from their mounts?
<p>
My point is that every antenna exists within the context of its environment and together it's a system. Some environments help the performance of your antenna system and some don't. Depending on frequency, this might not be the same for any location, or antenna design.
<p>
To be clear, an antenna system consists of the antenna, the feed line and the clips that hold it, the tuner, the radio and its power supply, the mount and the space around it, the radials, the tower, the pigeon poop on the wire, all of it.
<p>
Until recently my process to get any antenna to perform in a reasonable manner was to set it up, connect an antenna analyser, scan the appropriate range, tweak the antenna, scan again, rinse and repeat until it arrived at something approaching useful, or until it was good enough.
<p>
If you recall, I recently added some loading coils to a telescopic antenna to attempt to make it resonant on 10m, so I could connect my Weak Signal Propagation Reporter or WSPR beacon to it directly and leave it running independently from my main station.
<p>
I used the antenna analyser method, got it to the point where I had an antenna with a nice dip right at the required frequency and then watched it go completely sideways when I mounted the antenna in the window.
<p>
Having spent several hours getting to that point, I walked away and left it for another day. Today was that day. I again started on the floor of my shack and got nothing but an infinite SWR and no amount of tweaking could fix it. Right until the coax fell out of the SMA connector I was scratching my head.
<p>
After removing the faulty coax lead, I again tweaked the antenna and instead of using my antenna analyser, I fired up my NanoVNA, a tiny handheld open-hardware Vector Network Analyser or VNA. If you're not familiar, it's a standalone palm sized device with an LCD display and battery which will allow you to test most of your RF equipment. This little box came to me via a generous gift from a fellow amateur. It can repeatedly scan a range of frequencies and report in near real-time what's going on. Instead of waiting a minute after each adjustment, I could wait less than a second and immediately see the effect.
<p>
This has been a game changer.
<p>
I could mount the antenna against a metal surface and immediately see what the impact was. I could see the difference between it being mounted horizontally, where it would sag, to it being vertical where it stayed straight. I could see the steepness of the SWR plot, see how the low point moved around, up and down the band, see what the depth or lowest SWR was at any point. I could see my hand approaching the antenna, how nearby metal objects affect the antenna, what made it better and what made it worse.
<p>
The reason that I'm talking about this is because it's the very first time that I was able to actually get a feel for what affects an antenna, in what way and by how much.
<p>
To describe an analogy, it's like watching someone play a theremin and hearing how their hands affect the sound. If you're not familiar, a theremin is an electronic musical instrument controlled without physical contact by the performer, named after its inventor, Leon Theremin who patented it in 1928. From the outside it looks like a metal antenna that you bring your hands near to change the field. The changes are converted into sound.
<p>
The NanoVNA gives you the same level of feedback, but does so visually in a quantitative way, providing you with the insight to adjust your antenna to your liking and taking into account its entire environment.
<p>
Does this mean that I'm telling you to go out and buy one today? Well, that's not up to me, but I am intensely grateful for it arriving at my doorstep.
<p>
I'm Onno VK6FLAB
Listen:
How much antenna is enough?
Foundations of Amateur Radio
<p>
When you start in this hobby one of the most frustrating aspects is that of selecting the right antenna. If you've been around for a while, you'll discover that this continues to be the case, even when you've been licensed longer than I've been alive.
<p>
In the past I've discussed at length why that is the case, but to recap, consider a dipole antenna. In essence it's two pieces of wire that are connected to the radio via some form of feed-line.
<p>
Now consider the idea of changing the length of each wire. You could trim each end in the same way, or you could make one end longer than the other. You could fold the ends at an angle, or you could mount the dipole near the ground, or high up in the trees, you could position it vertically, or arrange the wires at an angle towards each other. You could make the wire thicker, or thinner, from different material or arrange the ends so they meet up in a circle, or a square, a triangle or some other shape.
<p>
You get the point, there is endless variation arranging this single antenna and I've not even discussed things like feed-lines, traps, chokes, counterpoise and other RF shenanigans.
<p>
With that in mind, amateurs around the world are attempting to improve their antenna system every time they get on air to make noise.
<p>
Recently I reported that my 10 mW WSPR, or Weak Signal Propagation Reporter beacon was heard 13,455 km away in Sweden by Mats SM3LNM on the 10m band. The signal report was -25 dB, which means that with an experimental cut-off for a successful decode at -34 dB, I have 9 dB to play with, so at least theoretically, I could reduce my power even further, to 1 dBm, or just over 1 mW and still make the distance.
<p>
The antenna I'm using is one built by Walter VK6BCP (SK). It's a 40m vertical antenna, helically wound on a fibreglass blank and clamped to the side of a metal pergola. The antenna is tuned to the 10m band using an SGC SG-237 antenna coupler, essentially a device that can add or remove inductance or capacitance to make my antenna appear resonant on the appropriate frequency. The antenna coupler in turn is attached to about 20 or 30 meters of 75 Ohm, quad shield RG6 which I have left over from my remote internet satellite dish installation days.
<p>
That's all to say that the antenna system for my beacon is sub-optimal and it's likely that my actual power output is lower than the 10 mW that my beacon is reporting.
<p>
So, with all that in mind, what else could I try?
<p>
I have an indoor telescopic antenna stuck to the window and I've been wondering if I can attach my beacon to it directly and leave it running without the need to worry about disconnecting the beacon when I'm wanting to fire up my actual station to make other noises on air.
<p>
A quick scan with the analyser reveals that the lowest frequency out of the box is about 60 MHz. I decided that adding some loading coils might help, so I set about fabricobbling an antenna, yes, you heard me, fabricobbling, fabricating and cobbling together.
<p>
Anyway, using 7mm thick drip irrigation riser poly pipe as a form I wound two coils with 1.25mm copper wire that I had lying around. Depending on which calculator you used, that was either too much or not enough for my needs. I managed 53 windings, shy of the planned 60, but still a good start.
<p>
Using the same irrigation riser, which as luck would have it managed to match the thread for the telescopic antenna elements and feed point, I separated each element by about 100 mm from the feed point, then used the two loading coils to connect the feed point back to each element. An hour later I now have a telescopic antenna, with two loading coils and as luck would have it, I'm much closer.
<p>
The resonant point is now 30 MHz, down from 60 MHz, so I have a little more tinkering ahead of me. I might change the wire and use some eyelets at the ends to make assembly simpler, but the general idea seems to work as intended.
<p>
If it doesn't work, I've come across a design for a 25.5 meter long End Fed Half Wave antenna that will work on anything between 80m and 10m and it appears that my driveway is just long enough to fit, but that will negate the indoor aspect of the antenna.
<p>
All this reminds me of the ugliest dipole I ever saw, in a bush shack, a decade ago, consisting of two wires, haphazardly soldered onto a piece of coax, looped around an insulator, with a piece of wire holding it together, tied between two trees. It was only ever meant to be temporary, but it was there for years. I used it to speak to stations all over the pacific and in the process learnt a lot about the performance of both my radio and the antenna connected to it.
<p>
The point being that experimentation in antenna building is what we're all about, even going backwards from multi-band, high gain antenna farms, back to basics and exploration.
<p>
In case you're wondering, I haven't forgotten about the Hustler 6BTV antennas packed in boxes. They're still very much part of the grand plan, but in light of my recent low power experiments, I'm getting very curious about using antennas that really stretch the propagation friendship. Why? Because I can.
<p>
What antennas have you built that you were ashamed of?
<p>
I'm Onno VK6FLAB
Listen:
Lost in space ...
Foundations of Amateur Radio
<p>
There is a fascination with space that arguably started long before the first time that human spaceflight was proposed by Scottish astronomer William Leitch in 1861. Names like Sputnik, Mercury, Gemini, Apollo and Columbia speak to millions of people and organisations like NASA, SpaceX and Blue Origin, to name a few, continue to feed that obsession.
<p>
In amateur radio we have our own names, things like ARISS, or Amateur Radio on the International Space Station, or its predecessor SAREX, the Shuttle Amateur Radio Experiment.
<p>
Today, stories about people making contact with the International Space Station continue to make news. We have school programs where amateur radio ground stations schedule a call to speak with an astronaut in space and we've been launching our own amateur satellites for a long time. Launched on the 12th of December 1961, OSCAR1, or Orbiting Satellites Carrying Amateur Radio was built by a group of California based amateur radio operators for 63 dollars. It operated for nearly 20 days, transmitting "Hi" in Morse on 144.983 MHz.
<p>
The first amateur radio space voice contact was made on the 1st of December 1983, almost forty years ago.
<p>
It's surprising that in the age of technology such a significant event has been so poorly recorded for posterity.
<p>
If you go searching for the actual audio, you'll discover several versions of this contact including varying transcripts. I've attempted to reconstruct the wording, but I've yet to hear a complete and unedited version. For example, there's an ARRL movie called "Amateur Radio's Newest Frontier" with out of sync audio. There's also an audio file with a transcript from an archived copy of a website by W7APD. The most recent one is on a video called "HAM - Official Documentary 2022", produced by students from the School of Visual and Media Arts program at the University of Montana and broadcast on Montana PBS on November 24th, 2022.
<p>
So, what follows is not necessarily complete, but calling from Space Shuttle Columbia it went a little like this:
<p>
"..U.S. west coast and calling CQ. Calling CQ North America. This is W5LFL in Columbia. In another 30 seconds I'll be standing by. Our spacecraft is in a rotation at the moment and we're just now getting the antenna pointed down somewhat more toward the Earth. So I should be able to pick up your signals a little bit better in the next few minutes. So W5LFL in Columbia is calling CQ and standing by. Go ahead."
<p>
"This is W5LFL in Colombia, W5LFL in Columbia, orbiting the Earth at an altitude of 135 Nautical Miles. Passing over the US West Coast and calling CQ. So W5LFL in Columbia is calling CQ and, ah, standing by. Go ahead."
<p>
"W5LFL on STS-9, WA1JXN, WA1 Japan X-Ray Norway, WA1JXN, Frenchtown Montana, WA1JXN standing by."
<p>
"Hello W1JXN, WA1 Juliet X-Ray November, this is W5LFL, I picked up your signals fairly weakly. I think our attitude is not really the best as yet, but you're our first contact from orbit. WA1 Juliet X-Ray November. How do you read? Over."
<p>
On board STS-9, Space Shuttle Columbia, was Dr Owen Garriott, W5LFL, now silent key. On the ground was Lance Collister, then WA1JXN, now W7GJ.
<p>
NASA published an Educational Brief for the Classroom that described Owen's set-up as a battery powered 5 Watt FM transceiver feeding a split-ring on a printed circuit board antenna that will be placed in the upper crew compartment window on the aft flight deck. Others reported that the radio was a Motorola handheld. Logging was done with a tape recorder velcroed to the transceiver.
<p>
Owen describes the antenna as a "well-designed, hand-held antenna, known as a 'cavity antenna', which could be velcroed to the window. It was about 24 inches in diameter and looked somewhat like a large aluminum (sic) cake pan"
<p>
There's an edited version of a similarly titled ARRL video called "Amateur Radio's Newest Frontier - ARRL documentary featuring Owen Garriot, W5LFL, on STS-9" showing the antenna as a copper tube, bent into a circle, mounted inside an open aluminium box that was hinged on the window to face outwards.
<p>
The NASA brief also described a range of frequencies and designated 145.55 MHz as the primary frequency over the United States. It included a whole section about synchronising clocks using WWV in Fort Collins, Colorado, odd and even minute transmission schedules and descriptions on how this should work.
<p>
Operating during time off, when the antenna was facing Earth, and being on air for about four hours during the mission, around 300 contacts were made across the globe.
<p>
Today we continue to experiment in space. The callsign N1SS is heard on-air regularly from the International Space Station, astronauts are often licensed radio amateurs, there's a permanent repeater on the ISS, we launch research spacecraft called nano-satellites or more popularly CubeSats for amateur radio at every opportunity. So far there's over 160 satellites and the adventure continues.
<p>
Speaking of experiments, albeit earthbound, the other day, my WSPR or Weak Signal Propagation Reporter beacon, using 10 milliwatts was heard 13,455 km away in Sweden, that's 1.3 Million kilometres per Watt.
<p>
What have you been up to in Amateur Radio lately?
<p>
I'm Onno VK6FLAB
Listen:
The Contester In Me...
Foundations of Amateur Radio
<p>
So, I have a confession to make. I'm a contester. I'm not ashamed of this. While I'm in a confessing mood, I'll also mention that I've not participated in many contests in the past few years. This is not for the want of desire, but for the lack of motivation to fix things in my shack that are fundamentally broken.
<p>
On the weekend I participated in a local contest. I took part for six hours, got on-air and made noise, made about 30 contacts, had a ball. I wasn't playing to win, though I did use the opportunity to refresh and hone some of my rusty skills.
<p>
The next day I spent much too long converting my log into something that the contest organiser asked for. I also discovered that there was a duplicate entry in my log, not something which I'd expect with only so few contacts, but a reflection on the tool I was using to create my log.
<p>
I started writing down what I learnt from the experience, operating from my own shack, documenting what worked and what didn't.
<p>
I commented on several things relevant to me, but to give you a flavour, my operator position is terrible because I'm logging on my main computer and the radio is side-on when I'm facing the computer. The sun was shining directly into my eyes when facing the computer. Holding a microphone I didn't have hands-free, I still don't have an auto-keyer to save my voice, my foot pedal didn't work and my data interface was on loan to another amateur.
<p>
As I said, these things are specific to me.
<p>
Logging was worse.
<p>
It didn't quite bring me to tears, but as the contest went on, it became a problem. I started to write down what was wrong with the tool I was using with a view to submitting patches to fix it when I realised that it wasn't actually built as a contesting logging tool, so I stopped and instead started writing a new list, one that describes what a good contesting tool looks like. It builds on a decade of using different tools and participating in contests in all manner of different situations, from special portable event activations, through to the annual top-tier contests run from a purpose built contest station and everything in between.
<p>
So, what does the ideal contesting tool look like, for me?
<p>
It needs to be cross platform, as-in, I should be able to use it on whatever computer I have access to, my Linux workstation, a Macintosh Laptop, an Android phone or tablet and while I'm at it, Windows and iOS and I think it should be able to run on a Raspberry Pi. In other words, there shouldn't be a situation where you cannot run the tool because you have some random combination of operating system or CPU that the developer doesn't support.
<p>
It must be open source. By that I mean, the code should be available to the entire community. There are too many stories of great tools dying or being held hostage by individuals or small groups. The tool should continue to exist and be usable regardless of the participation of the original developer. Users should be able to fix things, add functionality, change themes, whatever.
<p>
You should be able to customise it because not every contest needs the same information. For example, the John Moyle Memorial Field Day, a contest run every year during March in Australia requires that VHF and UHF contacts record the maidenhead locator, a four or six character message that designates the location of the station. This is used to calculate distance between two stations and award points accordingly. Such a requirement isn't needed in most other contests.
<p>
Some contests are considered friendly contests, like the Remembrance Day contest in August. It's common to exchange your name, details about your station and have a chat. You'd be unpopular if you used that approach for the Oceania DX, the CQ World Wide or the CQ WPX contests. In other words, some fields are expected for some contests, but not for others.
<p>
The tool needs to be able to show if a contact is valid by whatever means the rules for a particular contest decide. It needs to automatically log the time, keep track of previous entries and know about the super check partial list to validate partial callsigns.
<p>
The user needs to be able to use either a keyboard or mouse, or both, to do all the common contesting data entry. No dependency on crazy keyboard shortcuts, no requirement to click the mouse to make an entry, in other words, the tool needs to be able to get out of the way of the contester.
<p>
I think it needs to have a plug-in system to accommodate different rules and it needs to be able to export data in whatever format the contest organiser expects.
<p>
You should be able to use it without needing to be connected to the internet during the contest, it should be easy to update and have the ability to keep a station log for all the contacts ever made.
<p>
It would be great if it could also import existing logs so you can start to consolidate older logs.
<p>
Having spent quite some time looking for such a tool and failing, I've come to the conclusion that there's only one thing for it, I'm going to have to write my own tool and it would be great if you could help by sharing your opinion on the matter.
<p>
At this point I'm looking for suggestions on what you think is needed for a great contesting tool. I realise that for some, pen and paper is sufficient, and I'm not trying to dissuade you from using that, I've used it myself on more than one occasion, rather, I'm asking if you can think of things that it should do out of the box, things that are basic functionality that you would like to see as part of the design.
<p>
You can find the project on my vk6flab GitHub page, comment on Reddit, or you can drop me an email, cq@vk6flab.com.
<p>
Look forward to hearing from you.
<p>
I'm Onno VK6FLAB
Listen:
What's with a negative SNR?
Foundations of Amateur Radio
<p>
We describe the relationship between the power of a wanted signal and unwanted noise as the signal to noise ratio or SNR. It's often expressed in decibels or dB which makes it possible to represent really big and really small numbers side-by-side, rather than using lots of leading and trailing zeros. For example one million is the same as 60 on a dB scale and one millionth, or 0.000001 is -60.
<p>
One of the potentially more perplexing ideas in communication is the notion of a negative signal to noise ratio. Before I dig in how that works and how we can still communicate, I should point out that in general for communication to happen, there needs to be a way to distinguish unwanted noise from a desired signal and how that is achieved is where the magic happens.
<p>
Let's look at a negative SNR, let's say -20 dB. What that means is that the ratio between the wanted signal and the unwanted noise is equivalent to 0.01, said differently, the signal is 100 times weaker than the noise. In other words, all that a negative SNR means is that the ratio between signal and noise is a fraction, as-in, more than zero, but less than one. It's simpler to say the SNR is -30 dB than saying the noise is 1000 times stronger than the signal.
<p>
Numbers like this are not unusual. The Weak Signal Propagation Reporter or WSPR is often described as being able to work with an SNR of -29 dB, which indicates that the signal is about 800 times weaker than the noise.
<p>
To see how this works behind the scenes, let's start with the idea of bandwidth.
<p>
On a typical SSB amateur radio, voice takes up about 3000 Hz. For better readability, most radios filter out the lower and upper audio frequencies. For example, my Yaesu FT857d has a frequency response of 400 Hz to 2600 Hz for SSB, effectively keeping 2200 Hz of usable signal.
<p>
Another way to say this is that the bandwidth of my voice is about 2200 Hz, when I'm using single side band. That bandwidth is how much of the radio spectrum is used to transmit a signal. For comparison, a typical RTTY or radio teletype signal has a bandwidth of about 270 Hz. A typical Morse Code signal is about 100 Hz and a WSPR signal is about 6 Hz.
<p>
Before I continue, I should point out that the standard for measuring in amateur radio is 2500 Hz.
<p>
This is significant because when you're comparing wide and narrow signals to each other you'll end up with some interesting results like negative signal to noise ratios. This happens because you can filter out the unwanted noise before you even start to decode the signal. That means that the signal stays the same, but the average noise reduces in comparison to the 2500 Hz standard.
<p>
This adds up quickly. For a Morse Code signal, it means that turning on your 100 Hz filter, will feel like improving the signal to noise ratio by 14 dB, that's a 25 fold increase in your desired signal.
<p>
Similarly, filtering the WSPR signal before you start decoding will give you roughly a 26 dB improvement before you even start.
<p>
But there's more, since I started off with claiming that WSPR can operate with an SNR of -29 dB. I'll note that -29 dB is only one of the many figures quoted. I have described testing the WSPR decoder on my system and it finally failed at about -34 dB. Even with a 26 dB gain from filtering we're still deep into negative territory, so our signal is still much weaker than the noise.
<p>
There are several phenomena that affect the decoding of a signal.
<p>
To give you a sense, consider using a limited vocabulary, like say the phonetic alphabet, or a Morse character, the higher the chance of figuring out which letter you meant. This is why it's important that everyone uses the same alphabet and why there's a standard for it. To send a message, WSPR uses an alphabet of four characters, that is, four different tones or symbols.
<p>
Another is how long you send a symbol. A Morse dit sent at 6 words per minute or WPM lasts two tenths of a second, but sent at 25 WPM lasts less than 5 hundredth of a second This is why WSPR uses two minutes, actually 110.6 seconds, to send 162 bits of data, lasting just under one and a half seconds each.
<p>
If that's not enough, there's a processing gain. One of the fun things about signal processing is that when you combine two noise signals, they don't reinforce each other, but when you combine two actual signals, they do. Said in another way, signal adds coherently and noise adds incoherently.
<p>
To explain that, imagine that you have an unknown signal and you pretended that it said VK6FLAB.
<p>
If you combined the unknown signal with your first guess of VK6FLAB and you were right, the unknown signal would be reinforced by your guess. If it was wrong, it wouldn't. If your vocabulary is small, like say four symbols, you could try each in turn to see what was reinforced and what wasn't.
<p>
There's plenty more, things like adding error correction so you can detect any potentially incorrect words. Think of it as a human understanding Bravo when the person at the other end said Baker.
<p>
If you knew when to expect a signal, it would make it easier to decode, which is why a WSPR signal starts at one second into each even minute and each symbol contains information about when that signal was sent, which is why it's so important to set your computer clock accurately.
<p>
Another is to shuffle the bits in your message in such a way that specific types of noise don't obscure your entire message. For example, if you had two symbols side-by-side that when combined represented the power level of your message, a brief burst of noise could obliterate the power level, but if they were stored in different parts of your message, you'd have a better chance of decoding the power level.
<p>
I've only scratched the surface of this, but behind every seemingly simple WSPR message lies a whole host of signal processing magic that underlies much of the software defined radio world.
<p>
These same techniques and plenty more are used in Wi-Fi communications, in your mobile phone, across fibre-optic links and the high speed serial cable connected to your computer.
<p>
Who said that Amateur Radio stopped at the antenna connected to your radio?
<p>
I'm Onno VK6FLAB
Listen:
Acronym not found ...
Foundations of Amateur Radio
<p>
Our community is full of TLAs, or three letter acronyms. Some of them more useful than others. For example, I can tell you thank you for the QSO, I'm going QRT, QSY to my QTH. Or, thanks for the chat, I'll just shut up and take my bat and ball and go home.
<p>
Acronyms arise every day and it came as no surprise to spot a new one in the wild the other day, SHF. It was in a serious forum, discussing antennas if I recall, so I didn't blink and looked it up. Super High Frequency. Okay, so, where's that?
<p>
I'm familiar with VHF and UHF and as radio amateurs we're often found somewhere on HF, that's Very High Frequency, Ultra High Frequency and High Frequency if you're curious.
<p>
Turns out that the ITU, the International Telecommunications Union has an official list, of course it does. The current ITU "Radio Regulations" is the 2020 edition. It's great bedtime reading. Volume one of four, Chapter one of ten, Article two of three, Section one of three, Provision 2.1 starts off with these words: "The radio spectrum shall be subdivided into nine frequency bands, which shall be designated by progressive whole numbers in accordance with the following table."
<p>
When you look at this table you'll discover it starts with band number four and ends with band number twelve, between them covering 3 kHz to 3000 GHz. In position ten you'll see the designation "SHF", covering 3 to 30 GHz, centrimetric waves.
<p>
A couple of things to note.
<p>
The list starts at band four. There are of course frequencies below 3 kHz. The list ends at twelve, but there are frequencies above 3000 GHz. You'll also note that I'm not saying 3 Terahertz, since the ITU regulations specify that you shall express frequencies up to 3000 GHz using "gigahertz".
<p>
Interestingly the same document has a provision for reporting interference where you can report using Terahertz frequencies, so I'm not sure how the ITU deals with such reports.
<p>
Another thing to note is that this table doesn't actually define what SHF means. It's nowhere in the radio regulations either, I looked. I'm not sure where the words Super High Frequency came from. There is an ITU online database for looking up acronyms and terms. That leads to a document called "Nomenclature of the frequency and wavelength bands used in telecommunications", which also doesn't use "Super High Frequency" anywhere.
<p>
That said, using the ITU band four, where its definition starts, the VLF band, or Very Low Frequency, followed by LF, Low Frequency, MF, Medium Frequency, the familiar HF or High Frequency, VHF, UHF, then SHF and beyond that, EHF, Extremely High Frequency and THF or Tremendously High Frequency, yes, Tremendously High.
<p>
There's a report called the "Technical and operational characteristics and applications of the point-to-point fixed service applications operating in the frequency band 275-450 GHz". It introduces the term "THF which stands for tremendously high frequency" but adds the disclaimer that "this terminology is used only within this Report."
<p>
Seems that there are plenty of documents on the ITU website using that same definition, so I'm guessing that the cat is out of the bag. THF by the way is defined as being for 300 to 3000 GHz frequencies.
<p>
By the way, the ITU TLA finder exposes that THF stands for Topology Hiding Function. Where's a good acronym when you need it?
<p>
Speaking of definitions, I came across the definition of a "taboo channel" which according to the ITU is "A channel which coincides with the frequency of the local oscillator in the single super heterodyne receiver which is tuned to an analogue channel."
<p>
Anyway, we still have a way to go.
<p>
Below band four, less than 3 kHz, we have ULF or Ultra Low Frequency, SLF, Super Low Frequency and ELF, Extremely Low Frequency, which is defined as band one, between 3 and 30 Hz. Below that, some have suggested TLF, or Tremendously Low Frequency which apparently goes between 1 and 3 Hz with a wavelength between 300,000 down to 100,000 km. Others have suggested that this is an internet meme, but so far it seems to me that it has just as much legitimacy as any of the other wordings, since it appears that the ITU explicitly excludes such definitions, even if internal documents introduce terms from time to time.
<p>
It did make me wonder, what comes after Tremendously High Frequencies, Red?
<p>
Turns out, yes, well, infra-red pretty much follows on from Tremendously High Frequencies.
<p>
If you think that's the end of it, think again. The IEEE, the Institute of Electrical and Electronics Engineers has its own definitions, of course it does. Unfortunately they decided that you need to pay for their standard. It was first issued in 1976 "to remove the confusion". There's an xkcd comic called "Standards", number 927 if you're looking. It goes like this:
<p>
Situation: There are 14 competing standards.
14?! Ridiculous! We need to develop one universal standard that covers everyone's use cases. Yeah!
Soon: Situation: There are 15 competing standards.
<p>
Anyway, the IEEE designates that after UHF comes L or Long wave, followed by S, or Short wave, then comes C, the compromise between Short wave and X or cross or Exotic. Then there's Ku, Kurtz Under, K, Kurtz, and Ka or Kurtz above, Kurtz being the German word for Short. There's the V band and the W band which follows the V band.
<p>
Had enough yet?
<p>
NATO, the EU and the US define these using letters of the alphabet.
<p>
And broadcasters use Band Numbers which link up to nothing in particular.
<p>
I wonder if the measure of a society is just how many different ways can be used to describe the same thing. Perhaps we should have stopped at Hertz or Hz, which was established in 1930 by the International Electrotechnical Commission, as an expression of the number of times that a repeated event occurs per second, in honour of Heinrich Hertz.
<p>
One more three letter acronym, the International Electrotechnical Commission is better known as the IEC.
<p>
I wonder if the ITU is taking suggestions, ginormous, utterly, inordinately, awfully and humongously seem like perfect opportunities for future expansion.
<p>
I'm Onno VK6FLAB.
Listen:
Antenna Testing Day ...
Foundations of Amateur Radio
<p>
Last week I went outside. I know, it was a shock to me too. The purpose of this adventure was to test an antenna that has been sitting in my garage for nearly a year. Together with a friend we researched our options and at the end of the process the Hustler 6BTV was the answer to our question. Before the commercial interest police come out of the woodwork, I'll point out that I'm not providing a review, good or bad, of this antenna, it was the antenna I purchased and went to test.
<p>
Between the two of us we have three of these antennas. I have the idea to use one as a portable station antenna and another as my base station antenna. Glynn VK6PAW intends to use his as a base station antenna.
<p>
To set the scene. The antennas came in quite large boxes, just over six bananas long, or more than 180 cm. When they arrived I opened my boxes and checked their content, then sealed it all up and put the boxes on a shelf. Last week Glynn proposed that we set one up and see what we could learn from the experience.
<p>
You know that I love a good spreadsheet, so planning went into overdrive, well, I put together a list of the things we'd need, starting with the antenna and ending with sunscreen to protect my pasty skin from the fusion experiment in the sky. In between were things like an antenna analyser, spare batteries, tools, imperial, since apparently there are still parts of the world that haven't gone beyond barley measurements. I jest, they authorised the use of the metric system in 1866. My list also included a magnetic bowl to capture loose nuts and washers, you get the idea, anything you might need to test an antenna in the field.
<p>
Our setup was on a rural property where we had lovely shady trees and oodles of space to extend out a 25m radial mat. We tested many different set-ups. I won't go through them all, but to give you an idea of scale, in the time we were there, we recorded forty different antenna frequency scans. The 6BTV antenna is suitable for 80m, 40m, 30m, 20m, 15m and 10m. We tested with and without radials, raised and on the ground and several other installations.
<p>
We learnt several useful things. For starters, sitting on the ground with radials the antenna measurements line up pretty well with the specifications and with a suitable base mount to protect the plastic base the portable station antenna is usable out of the box.
<p>
Any variation on this will result in change, sometimes subtle, sometimes less so. For example, we came up with one installation where the SWR never dropped below 3:1. That's with the antenna on the ground without any radials in case you're wondering.
<p>
Other things we learnt were that manually scanning each band is painful. When we do this again we'll have to come up with a better way of measuring. The aim for my base antenna is to install it on my roof, bolted to a clamp on the side of my metal pergola. This means that we're going to have to do some serious tuning to make this work for us. It might turn out that we'll start with installing the antenna at Glynn's QTH first, but we haven't yet made that decision.
<p>
Other things I learnt are that I had actually put together the base clamp when I checked the boxes a year ago, so that was a bonus. The magnetic bowl saved our hides once when a spring washer fell into the lawn. The hose-clamps that come with the antenna require a spanner, but there are thumb screw variations of those that I'll likely use for my portable setup.
<p>
Other things we need to do is learn exactly how the traps work and how adjusting them affects things. In case you're unfamiliar with the concept of a trap, think of it as a radio signal switch that lets signals below a certain resonant frequency pass and blocks signals above that frequency. In other words, a 10m trap resonates just below 28 MHz. It lets frequencies below 28 MHz pass, but blocks those above it, essentially reducing the length of the antenna to the point where the trap is installed.
<p>
One test we did was to only use the base and the 10m trap. We discovered that this doesn't really work and that the metal above the trap, as-in the rest of the antenna, isn't just for show, even though it's on the blocked side of the 10m trap.
<p>
Given that I intend to use my base antenna as my main WSPR transmission point, I need to adjust things so the antenna works best on WSPR frequencies. I intend to use a tuner for when I want to work outside those frequencies.
<p>
One unexpected lesson was that the awning that Glynn attached to his vehicle was an absolutely essential item. I don't think I'll ever go portable again without one. Life changing would be an understatement. I'm investigating if I can fit one to my vehicle.
<p>
Having had some health issues over the past months I was anxious about going outside and being somewhat active. I paced myself, protected my back, took regular breaks, sat down a lot, drank litres of water and slept like a baby that night. No ill effects, very happy.
<p>
As a bonus, I even transferred our measuring data to a spreadsheet.
<p>
I can't wait to see the results of our next adventure.
<p>
Oh, we did connect a radio. Heard a beacon in Israel, heard a QSO in Italy, listened to WWV on 10 MHz and almost missed the bliss of not having to tune or switch when moving from band to band.
<p>
What have you been up to in the great outdoors?
<p>
I'm Onno VK6FLAB
Listen:
Are all spiky antennas the same?
Foundations of Amateur Radio
<p>
The world is filled with antennas. You'll find them on towers, buildings, cars and on your next door neighbour's roof. They come in an astonishing variety, to the point where you might start thinking that antennas are a fashion accessory that vary with the season and if you start digging through the history books you'll come across designs that dial that variety up to eleven.
<p>
Possibly the most visible antenna today is the television antenna and when you start noticing them, the more variation you'll discover.
<p>
Their basic shape consists of a vertical pole, the mast, with a horizontal pole, the boom. Attached to the boom are various different shapes, or elements, that often vary in length according to some pattern.
<p>
The shape is designed to collect as much electromagnetic radiation from a particular direction, or in the case of a transmitter, focus as much energy as possible into one direction. This focus is called gain. The more focus, the more gain.
<p>
One of the oldest designs for this kind of antenna, still in use today, is the Yagi-Uda or Yagi antenna. It was invented in 1923 by Shintaro Uda at the Tohoku Imperial University in Japan and popularised to the English speaking world by his boss Hidetsugu Yagi who claimed to be the sole inventor in his Japanese patent application. He went on to file similar patents in Germany and the United States.
<p>
Gain for a Yagi varies depending on design. Generally more elements means more gain. Sometimes you'll see a Yagi with weird shorter elements along the boom. This is a design to make the antenna work across multiple frequencies. Another way that this can be achieved is by adding traps along an element. They look like a thick stubby tube at some distance along an element. You can have more than one of these to allow for more frequencies. These improvements allow for several Yagi antennas to share elements and boom space, essentially combining several independent antennas into one.
<p>
It can be tricky to discover in which direction a Yagi is pointing, but essentially the boom indicates the direction and the end with the shortest element is the front.
<p>
There's another type of antenna that to the casual observer looks similar. It's called a log periodic dipole array, LPDA or log periodic antenna. It was invented in 1952 by John Dunlavy whilst he was contracted to the United States Air Force. He wasn't credited because it was classified as "Secret", later changed to "Restricted". In 1958 Dwight Isbell built a log periodic antenna as an undergraduate student at the University of Illinois at Urbana-Champaign. He was part of a larger team that included Raymond DuHamel, John Dyson and Robert Carrell. Later Paul Mayes developed a variant that improved performance.
<p>
Before I dig in, I'll also note that this antenna caused all manner of legal issues that are still in force today. The so-called Blonder-Tongue Doctrine states that a patent holder isn't permitted to re-litigate the validity of a patent that has been held invalid previously. It was a result of the University attempting and ultimately failing to protect its patent for the widely copied antenna design. Reading about this is a fascinating discovery in how a single Judge can make a massive impact on law and society.
<p>
The log periodic antenna is designed in a way that to the uninitiated looks very similar to a Yagi antenna. It's based on the idea that you can design an antenna made up from independent dipoles that are spaced in such a way that they form an antenna where each dipole radiates to take advantage of its neighbours. Generally a log periodic antenna looks like a triangle. Often the elements are on two separate booms, alternating side-to-side, or you'll see a zig-zag structure that causes the antenna signal to alternate side-to-side.
<p>
One characteristic of an antenna is called bandwidth. It's a measure of how many frequencies it can operate on within the constraints of the antenna. The wider the bandwidth, the more frequencies you can use with the same antenna.
<p>
A Yagi antenna typically operates within about four percent of the design frequency. If you combine multiple Yagis by adding traps or different length elements, you'll end up with several frequencies, each with a similar range.
<p>
A log periodic antenna on the other hand is designed to be used across a large range of frequencies. In shortwave broadcasting there are log periodic antennas that operate between 6 and 26 MHz. In more common use today you'll find log periodic antennas used for higher frequencies. It's not unusual to find log periodic antennas that operate between 400 and 4000 MHz.
<p>
For even more confusion, you can share the boom of a log periodic antenna with a Yagi antenna as is popular in fringe television reception areas.
<p>
Some other things to note are that for a Yagi most of the elements are passive and only one is generally a driven element, in a log periodic antenna all elements are driven. For a Yagi antenna, more elements means more gain, whereas for a log periodic antenna it means more frequencies.
<p>
I'll also point out that there are experiments where the frequency range for Yagi antennas is being increased to more than twenty percent of the main frequency by varying the design. Much of this is achieved by using computer simulations to test many different virtual antennas until one promising design pops out. This optimisation technique can also be applied to log periodic antennas resulting in very interesting shapes that look nothing like the antennas you see on the roof today.
<p>
I've completely skipped over how these antennas are actually fed, as-in, how is the coax connected to the antenna. That's a whole different topic of conversation worthy of many hours of research and discussion.
<p>
Next time you look at a spiky antenna you should be able to discover if it's a Yagi or log periodic, or both and why.
<p>
I'm Onno VK6FLAB
Listen:
Some Amateur Radio ABCs ...
Foundations of Amateur Radio
<p>
A is for Antenna, the eyes and ears of any amateur station. You'll spend eighty percent of your life attempting to get twenty percent improvement for any antenna you'll ever use.
<p>
B is for Balun, bringing together the balanced and unbalanced parts of your antenna system.
<p>
C is for Coax, the versatile conductor that snakes into your station, one roll at a time.
<p>
D is for Dipole, the standard against which all antennas are measured, simple to make, simple to use and often first in the many antenna experiments you'll embark on in your amateur journey.
<p>
E is for Electron, source of all things RF, the beginning, middle and end of electromagnetism, the reason you are an amateur.
<p>
F is for Frequency, the higher you go, the faster it happens.
<p>
G is for Gain, measured against a baseline, you'll throw increasing amounts of effort at getting more, one decibel at a time.
<p>
H is for Hertz, Heinrich to his mother, the first person to transmit and receive controlled radio waves in November of 1886 proving that James Clerk Maxwell's theory of electromagnetism was correct.
<p>
I is for Ionosphere, the complex and ever changing layers that surround Earth which led radio amateurs to discover HF propagation in 1923.
<p>
J is for JOTA, the Jamboree On The Air where radio amateurs, guides and scouts come together on the third full weekend of October to share global communications.
<p>
K is for Kerchunk, the sound caused by the local repeater that brings a smile to the operator and a grimace to the listener, created by pushing the talk button and not saying anything.
<p>
L is for Logging, the only way you'll ever remember who you spoke to and when and the perfect excuse for bragging to your friends after you managed to collect contacts all over the globe.
<p>
M is for Modulation, adding information to a radio signal by varying the amplitude, frequency, or phase.
<p>
N is for Net, a social excuse for getting on air and making noise with your friends.
<p>
O is for Oscillator, making repeating currents or voltages by non-mechanical means.
<p>
P is for Prefix, the beginning part of an amateur callsign that identifies your country or region of origin.
<p>
Q is for QRP, the best way to make just enough noise to make yourself heard, low power is the way to go!
<p>
R is for Resonance, the point where a circuit responds strongly to a particular frequency and less to others, used every time you tune a radio or an antenna or both.
<p>
S is for Shack, the space you call home, where you live your radio dream. The size of the corner of the kitchen table, the back-seat of your car or a purpose built structure with never enough space, no matter how much you try.
<p>
T is for Transceiver, a single box that contains both a transmitter and receiver that share a common circuit.
<p>
U is for UTC, Coordinated Universal Time, the only time zone that radio amateurs should use for any activity that goes beyond their suburb.
<p>
V is for VFO, the Variable Frequency Oscillator that provides radio amateurs with frequency agility, the means to listen anywhere, any-time.
<p>
W is for Waterfall, which displays radio signals across multiple frequencies at the same time.
<p>
X is for XIT, Transmit Incremental Tuning, changing your transmitter frequency whilst listening on the same frequency, helpful when you're trying to break through a DX pile-up.
<p>
Y is for Yagi, or Yagi-Uda antenna, the most popular directional antenna invented in 1926 by Shintaro Uda at the Tohoku Imperial University in Japan and popularised to the English speaking world by his boss Hidetsugu Yagi.
<p>
Z is for Zulu, the last word in the phonetic alphabet that every amateur should know and use.
<p>
73 is for best regards. Saying goodbye is hard to do, this says so without fanfare and clears your station from the air.
<p>
I'm Onno VK6FLAB
Listen:
Do you really know when the best time is to go on air?
Foundations of Amateur Radio
<p>
Getting on air and making noise is a phrase that you've likely heard me repeat often, actually, this will be the 24th time or so. It's an attempt at encouraging you to actually transmit and use the radio spectrum that is available to you. It's a nicer way of saying: Use it or lose it!
<p>
One of the more frustrating aspects of our hobby is finding other people to interact with. At the beginning of your hobby you have access to all these magic radio frequencies with no idea on how to use them. Often a new amateur will turn on their radio, call CQ a couple of times to see if there's anyone out there, hear nothing and give up.
<p>
As you get more experience you'll discover that radio frequencies change over time and that some work better at certain times of the day. This is reinforced by others who will talk to you about propagation, the solar cycle and how the ionosphere and its various so-called layers will change and what you can achieve throughout the day, the year and the long term cycle.
<p>
Armed with all this knowledge you are likely to get to a point where you make noise on a certain band depending on the time of day.
<p>
For example, experienced amateurs will avoid the 10m band at night because it's a so-called day-time band, in other words, their perception is that you cannot make contact on the 10m band after sunset and for the same reason, it's not suitable for early morning contacts.
<p>
What if we could test that perception and see if it's true or not?
<p>
Turns out that we have a perfect dataset to discover what actually happens. If I look at the 10m band WSPR or Weak Signal Propagation Reporter data for the past year, a year that had me using a beacon pretty much 24 hours a day, you'd expect that you could see just which times worked and which ones didn't. Turns out that regardless of time of day, my beacon was heard across every hour of the day. Of course the numbers aren't uniform across the day. The peak is at noon local time, the trough is at 5 am local time, 10% of reports are at noon, about 1.5% at 5 am. In other words, the worst time of day for my beacon to be reported is 5 am in the morning and it's not zero.
<p>
Interestingly the same isn't true for the signal to noise ratio, a measure of just how weak or strong a signal is in comparison to the local noise at the receiver. If you account for differences in transmitter power, meaning that a stronger transmitter is measured in the same way as a weaker one, the 10m band has the best signal to noise ratio at my location at 9 pm local time and the worst at 4 pm local time.
<p>
Given that I'm only using the 10m band with my beacon I also looked at the local OF78 grid square across all bands. It shows that reports are not directly related to when the average signal to noise is best. It seems to me that people are transmitting when they think it works best, not when it actually works best and I'll mention that the definition of "best" depends on each user.
<p>
Note that I haven't yet sat down to discover if there are automatic transmitter and receiver pairs that have been reporting 24/7 across a year on the same band to determine if there is more to learn about the relationship between how often something is reported and what the signal report was at the time. I can say that it's likely that your favourite band is more popular when others think it's popular, not when the conditions are better.
<p>
Consider for example that there are no local reports on the 12m band at 10am, but there are at 9am and 11am, so, was the band magically unusable the whole year at that time, or did people just not use it? The same is true for 160m. No reports at all before 5pm or after 3am, despite the bands around it having contacts throughout the day.
<p>
I will point out some things I've ignored. For example, what is a useful contact? Is it measured by distance, by quantity, by uniqueness? Is this choice the same for each band? Is it reasonable to compare a whole year, or should it be by some other time period, like month, season or lunar month? What is the signal to noise ratio for a band that's considered closed?
<p>
I'm mentioning this because each of those will directly affect what it looks like when you create a chart and it's likely to change what works best for you.
<p>
So, next time you get on air, try a band that shouldn't work according to your knowledge and see what happens. Perhaps you'll get lucky, make a contact and discover something unexpected.
<p>
I'm Onno VK6FLAB
Listen:
The evolution of software in radio ...
Foundations of Amateur Radio
<p>
The amateur community is nothing if not entertaining. Look at any discussion about a mode like FT8 and you'll discover people who describe it as the dehumanising end of the hobby. In the same thread you'll find an amateur who's been licensed longer than I have been alive who welcomes it using words like revitalising, more active, and the like.
<p>
If you're not familiar, FT8 is one of many weak signal digital modes that gained popularity over the past years during the most recent solar minimum when long distance HF propagation was challenging.
<p>
That example discussion was about the visible end of a mode like FT8, but there's an often overlooked all but invisible aspect of these modes that is much more significant, namely the popularisation of signal processing in software.
<p>
In many ways amateur radio is more about receiving than transmitting. This might not be obvious, but what's the point of transmitting if you cannot receive? Using software to do the listening makes for an interesting evolution that might be hard to grasp if I start digging into the fundamental algorithms that make this happen, instead let me describe a process that is easier to explain.
<p>
Imagine that there's a piece of software that knows how to decode digital signals. As the user of that decoding software, or decoder, you send audio into one end and callsigns and grid-squares come out the other end. How it does this isn't important right now.
<p>
We measure the quality of this decoder by how many times it correctly does this, in other words, how many times a correct callsign and grid-square comes out. The decoder can be improved by changing the way that the decoding process works. If the number of correct callsign and grid-squares that come out increases, the quality of the decoder is improved.
<p>
Now imagine that the decoder spits out the callsign 7N5EC with the grid-square OF78. This particular combination emerged as a WSPR decode on the 10th of December 2022. It was reported by AA7NM as a 100 Watt signal, 14,882 km away on the 40m band. The signal report was -30 dB.
<p>
If you know where OF78 is, you'll immediately spot a potential problem, if not, I'll help you out, OF78 is located near Perth in Western Australia. It's unlikely that a transmitted callsign in that part of the world starts with anything other than VK6. Mind you, a weather balloon with an odd callsign could theoretically be overhead in that location, but I've not yet heard of a 100 Watt transmitter on 7 MHz that someone hung from a weather balloon.
<p>
Another problem is that 7N5EC is a callsign that appears to be Japanese. It starts with 7N which is part of the Japanese callsign block, but the next symbol is the number 5 and at least according to the research I was able to do is not actually a currently valid callsign. The prefix 7N4 is allocated to the Kanto region on Honshu island, the largest island in Japan. 7N5 doesn't seem to be valid as a prefix. Ironically, that callsign will now exist on the Internet as soon as this article is published, but that's a whole other problem.
<p>
Either way, the chances of the combination of the callsign 7N5EC with the grid-square OF78 is unlikely to be correct. It gets even less likely if you consider that the callsign was reported only once in fifteen years and over 500 million WSPR decodes, I checked.
<p>
That means that if you updated the software to ignore that particular decode, you'd have improved the decoder by removing an incorrect combination. You could keep doing this by checking callsigns against grid-squares and against allocated callsigns and you'd have made a higher quality decoder.
<p>
Before you start arguing that this isn't fair, it's exactly the same process as the super check partial list does for people operating in a contest. The idea being that if you only recognise known contesting callsigns, you've got a better chance of making contact.
<p>
Think of it as a way of filtering out potentially incorrect callsigns. It still leaves the operator having the option to ignore the suggested callsigns and listen to what's actually coming in.
<p>
I realise that this is not how you would realistically improve a digital signal processing decoder, but it's an example of how changing the software can change the quality of a decoder and that was the point of this example. In reality you'd attempt to discover how this decode happened and what caused it to be wrong.
<p>
If you want to consider a more signal centric example, consider a decoder that starts with a first attempt at making a decode. With a single decode, it can then remove that known signal from the original audio and start another decoding cycle. You can repeat this as many times as you want until you end up with gibberish. Essentially this is an example of how a modern decoder can improve its performance.
<p>
This is why signal processing in software is so powerful and important and why FT8 and the rest of the digital firmament are here to stay. I should point out for those wondering, FT8 and WSPR are examples of simple messages, but there's nothing stopping us from using digital messages like this to exchange little bits of audio, or video, or something else. It's how mobile phones work today and at some point amateur radio is going to extend the envelope and come up with the next thing, it always has.
<p>
So, FT8, it's changing amateur radio, but not because we're glued to a screen having our computer talk to another one, but because it represents digital signal processing in software and it's just the beginning.
<p>
I'm Onno VK6FLAB
Listen:
Path loss and very small numbers ...
Foundations of Amateur Radio
<p>
Sometimes you learn mind boggling things about this hobby, often when you least expect it. Recently I discussed having my 20 mW WSPR or Weak Signal Propagation Reporter beacon heard on the other side of the planet, in Denmark, 13,612 km away. That in and of itself is pretty spectacular, but it gets better if you consider just how weak the signal was by the time it got there.
<p>
In radio communications there is a concept called path loss or path attenuation. Until recently I understood this to mean the things that impede a signal getting from transmitter to receiver. That includes coax and connector losses, refraction across the ionosphere, reflection off the surface of the planet and diffraction around objects.
<p>
It turns out there is another factor called "Free Space Path Loss" to consider. It's loosely defined as the loss of signal strength between two antennas. The name sort of implies that something happens to the signal in free space, which is odd if you know that in space, radio waves, regardless of frequency, travel without loss and will travel pretty much indefinitely.
<p>
So what's going on?
<p>
To get started, think about a dome lawn sprinkler, one of those little round discs that sits on the ground with the hose connected to the side. You turn on the tap and the water sprays in all directions. If you're really close to the sprinkler when the tap is turned on you'll get sopping wet almost immediately, since most of the water will hit you directly. This is particularly fun in the heat of summer on New Years Day in Australia, not so much in the middle of winter on the other side of the globe.
<p>
If you stand a couple of meters away, you'll still get wet, eventually, but it will take much longer, because most of the water isn't hitting you. If you stand even further away and assuming the water still gets that far, it will take even longer.
<p>
A small towel and a big towel will both take the same length of time to get wet if they're held at the same distance from the sprinkler, but if you wring them both out, you'll discover that the big towel captured much more water during the same time.
<p>
In radio communications we can combine these two ideas, the distance and the size of the receiver, to describe free space path loss.
<p>
The further away from the transmitter you are, the less signal is available to you to capture since much of the signal is not heading in your direction and the bigger your antenna, the more signal you receive. The bigger the antenna, the lower the frequency, which is why you'll discover that free space path loss is dependent on both distance and frequency.
<p>
To give you an idea of scale, the free space path loss for 28 MHz over 13000 km is about 144 dB.
<p>
While the name "Free Space Path Loss" implies loss of signal across the path in free space, the loss is not due to distance as such, rather it's caused by how much the signal is spread out in space. Similarly, there isn't more loss because the frequency is increased, it's that less signal is captured by the smaller size or aperture of the antenna required for a higher frequency.
<p>
So perhaps a better name might be Spherical and Aperture Loss, but then everyone would have to learn how to spell that, so "Free Space Path Loss" it is.
<p>
I'll point out that this is the minimum theoretical loss, in reality the loss is higher than this, since it also includes all the other parts of the path loss which are things that we can control, like coax and connector loss, and things we can improve by frequency selection, like ionospheric reflection and refraction which depend on solar conditions.
<p>
The one aspect of path loss that we have no control over is the "Free Space Path Loss", so perhaps that's why we don't talk about it very much.
<p>
I'll mention that in path loss calculations often antenna gain at the transmitter and receiver are used to reduce any path loss figures. If I have an antenna with 6 dB gain, then that reduces my overall path loss by 6 dB, which is why we spend so much time and effort figuring out what antenna to use when we get on air to make noise.
<p>
I mentioned that the free space path loss for my beacon between Australia and Denmark was about 144 dB. This means that my 20 milliwatt signal arrived in Denmark as a -131 dBm signal. That might not mean much, but that's the equivalent of about 80 attowatts. If you're not sure how big that is, 1 milliwatt is 1 quadrillion attowatts, a 1 with 15 zeros. Said another way, 1 watt is 1000 milliwatts, 1 milliwatt is 1000 microwatts. 1 microwatt is 1000 nanowatts, 1 nanowatt is 1000 picowatts, 1 picowatt is 1000 femtowatts, 1 femtowatt is 1000 attowatts.
<p>
It might come as a surprise, but these numbers are not unusual. Don't believe me? When your radio shows an S0 signal on HF, it is defined as -127 dBm, so we deal with tiny numbers like this all the time, we're just not quite aware of it on a daily basis.
<p>
Remember, my numbers are theoretical only, to give you an idea of scale. In reality everything in the path between the transmitter and receiver affects what ends up at the other end and might make the difference between hearing someone, or not.
<p>
I'm Onno VK6FLAB
Listen:
What is the difference between handheld, mobile and a base radio?
Foundations of Amateur Radio
<p>
If you've ever been in the market for a new radio, and truth be told, who isn't, you'll find yourself faced with a bewildering array of options varying from obvious to obscure and everything in between. At the obvious end of the scale are things like price, bands and transmit power and at the other end are things like Narrow Spaced Dynamic Range, which you'll find explained by Rob NC0B on his sherweng.com website where he's been publishing receiver test data for many decades.
<p>
One of the more subtle options you'll need to consider are handheld, mobile or base radio.
<p>
This is harder than you might think, since radios are increasing in functionality every time you wake up and if you look long enough, you'll discover that they're getting smaller at the same rate. Once upon a time you could just look at the size of a radio and define it as belonging in one or other category, but that's no longer a useful distinction. For example, my PlutoSDR is a tiny device, fits in my pocket, but there's no way I'd consider it a handheld, or even a mobile radio.
<p>
You might think that a bigger box has more stuff inside, costs more and performs better.
<p>
For example, the Drake R-4C receiver and companion T-4XC transmitter require external power and were once rated by the ARRL as very good. In reality the Drake R-4C performed terribly in a CW contest, incidentally, that was what caused Rob to start testing radios in 1976. That receiver and transmitter manage to cover 80m, 40m, 20m, 15m and 10m and together weigh in at 14.3 kg. They're considered a base radio.
<p>
The Yaesu FT-817, runs on batteries, weighs in at just over a kilogram and can be carried with a shoulder strap. It comes as a single device and covers many more bands than the Drake transmitter and receiver do, it would be considered a mobile or even portable radio. Obviously it would be hard to jam a Drake into your car or strap it to your belt, but does that mean that you cannot use an FT-817 as the base radio in your shack?
<p>
In case you're curious, the slightly beefier brother to the FT-817, the mobile FT-857d, is sitting on my desk as my current base radio. Has been for years.
<p>
So why do manufacturers continue to make this distinction between handheld, mobile and base radio? One look at the nearest radio catalogue will tell you that it's not based on either performance or price, not even close. You can buy a handheld with more functionality for the same price as a mobile radio and that same is true when you compare a mobile radio to a base radio.
<p>
Radios vary in price from $20 to $20,000. A cynical person would suggest that pricing is based around extracting the most money from your pocket, but a more charitable explanation might be that physical size dictates things like the number of buttons you can fit on a radio, how many connectors can be accessed before the radio flies off the desk from the weight of the coax hanging off the box, how big is the display and other such limitations.
<p>
I'm not being glib when I use the word charitable, since much of modern transceiver design revolves around software which can pretty much fit in any box. Using external computers, neither buttons nor a display are needed, leaving external connectors, which if we're being really honest could all fit in a box that would fit in your pocket.
<p>
At this point you might wonder if handheld, mobile or base has any meaning at all. As I said, in most cases it doesn't. There's really only one place left where this matters, and that's when you have access to strictly limited space and power if you need to put the radio in your pocket or cram it into your car.
<p>
For your home shack, the distinction is unhelpful for most, if not all, amateurs.
<p>
Don't believe me? The Yaesu FT-710 currently ranks fourth on Rob's Sherwood Engineering Receiver Test Data List. It's a quarter the size of the top radio and it's sold as a "Base/Portable Transceiver". Yaesu calls it "Compact". It might not fit in the dashboard of my car, but it will fit on the folding table we use during field days.
<p>
That isn't an exception either. The Elecraft KX3 is the smallest radio on the first page of Rob's Receiver Test Data list. It fits in your pocket.
<p>
Before you start collecting statistics for each radio, I should point out that the more you know about this hobby, the harder this process becomes, so be careful. That said, if you have a massive list of anything to choose from, a new amateur radio, pet food, car, what to have for dinner, whatever, here's a process that will guarantee a result.
<p>
It works by eliminating one item at a time until you're left with your preference.
<p>
To start, grab the first two items on your list and pick the best one between the two. Ignore everything else, just those two items. You're going to fret about the definition of "best", but don't worry, since every time you do this, you'll have a different idea. All you're doing is saying, all things being equal, between these two options, which one do I prefer. No need to describe why, just pick one. In picking one, you've removed one option from the list.
<p>
Now, compare the winner to the next item on the list, again, ignore everything else and pick one and remove the other. Keep doing this until you run out of items. You'll end up with the single option that wins, for whatever reason, from the entire list.
<p>
Now, about that radio. All I need is the next paid project.
<p>
I'm Onno VK6FLAB
Listen:
What should we be learning?
Foundations of Amateur Radio
<p>
It's an immersive effort to create an article every week, so much so, that I've only just discovered that I passed the 600 article mark some time ago. I'd open up a bottle of something celebratory if I thought it warranted the effort, but I'd rather talk about amateur radio and what I've learnt since becoming licensed in December of 2010.
<p>
This hobby, this community, the activity of amateur radio keeps surprising me in unexpected and exciting ways. I know that there is a part of the community that thinks of this as a dying hobby, but with every fibre in my being I know this to be wrong. We explore, test, build and learn at every opportunity. Put any two amateurs in contact with each other, either physically or over the air and you'll soon witness an exchange of ideas, of things that bring joy, hints of the next thing and the next.
<p>
The inspiration for my writing comes from all manner of places. For example, here's an opinion recently shared by someone on social media:
<p>
"Basic antenna modeling using software should be included in ham radio licensing exam syllabus if it's not currently." [sic]
<p>
As opinions go it's one of the tamer ones I've come across, but it's not unique in any sense of the word. I've heard it described bemoaning the missing knowledge of new digital modes or the need to upgrade my license, or the idea that the introductory license should come with a fixed expiry date. You might have heard similar ones, phrased along the lines of a missing attribute that new licensees should be required to learn or know about before they can call themselves amateurs.
<p>
It's also completely unhelpful.
<p>
Let me explain why.
<p>
I'll start with an analogy. When was the last time your driver's license expired because you didn't upgrade it due to new road rules, new vehicle types, new car accessories or speed limits? In case you're confused, the answer is: never.
<p>
Does amateur radio cause death and mayhem in the community? No.
<p>
Do cars?
<p>
So, in the scheme of things, even if amateur radio can be used to help save lives, it's not an activity that's generally considered life threatening. You could argue that radio amateurs could cause life threatening interference, and technically they can. So can any user of any piece of radio equipment, CB radio, mobile phone, Wi-Fi, you name it. Even a half asleep electronics student in their first year of high-school could do this. The skill isn't specific to radio amateurs.
<p>
So, what is this about, the requirement for antenna modelling, or some other missing skill, and why does our community keep getting flooded with such, frankly, nonsense?
<p>
In my opinion, it's the same phenomenon that laments the loss of Morse code, the fact that we lost the 11m band, that we're playing with FT8 instead of AM, that we prefer integrated circuits to valves. The world is a flowing feast and amateur radio is along for the ride. Stand still and the world moves on.
<p>
Should amateur radio licensing change?
<p>
Absolutely!
<p>
It should move with the times. It should lower the barrier to entry at every opportunity. It should explore the possible, not the requirements of a select group of people who decry the dumbing down of the hobby and want to pre-load every license exam with things that are absolutely irrelevant to the turning on of a radio and making noise.
<p>
Will amateurs benefit from knowing that antenna modelling software exists? Sure they will. Just like they'll benefit from knowing about valves and Morse code. That doesn't mean that they should be part of the exam process. I want new amateurs, no, all amateurs to be curious, to ask, to discover, to explore and to want to know stuff, not because it's a requirement to get a license, but because it's beneficial to their amateur journey.
<p>
Every week I come up with a different way to look at our hobby because this hobby is so divers. I've used the phrase a 1000 hobbies in one. So far I've just scratched the surface, some 600 weeks in. We'll see where we're at when I've held my license for another decade or so.
<p>
So, have at it. What is missing from the current exam and why should it be included?
<p>
I'm Onno VK6FLAB
Listen:
Where does propagation data come from?
Foundations of Amateur Radio
<p>
One of the many questions that new amateurs ask is, "When should I get on-air, and on what band?" The often-heard reply is just to get on-air and make some noise. As time goes by, the importance of this seems to fade in favour of using HF prediction tools. Some amateurs never venture beyond that point, relying almost exclusively on technology to determine if they should turn on their radio or not.
<p>
If you search the internet for "current HF conditions", you'll end up with dozens of sites boldly claiming to provide precisely that information, some even using the label "Real-Time". You'll find instructions from countless self-proclaimed "experts" on how to read propagation conditions from their favourite site. There's even widgets that you can install on your website displaying propagation data per amateur band with helpful labels like "Band Closed" or showing conditions as "Poor", "Fair" or "Good". Some of these widgets even include an embedded time-stamp to prove just how "current" the information is.
<p>
If that's how you decide to activate your amateur station, like I once did, I have some questions.
<p>
Where is this information coming from, is it accurate, and when was it last updated?
<p>
To give you an idea of just how complex this question is, consider visiting two popular websites, solarham.net from Canada and spaceweatherlive.com from Belgium. On their home-pages, you'll find all manner of numbers, charts, photos, events, notifications, alerts, and warnings, each related in some way to HF propagation and the condition of the Sun.
<p>
Sounds great, excellent resources, job done.
<p>
Well, no.
<p>
Let's start simple. Location.
<p>
Leaving aside where the site's owner is or where the servers are, both potential sources of confusion, consider where you are and where the remote station is that you're trying to contact. Now compare that with the propagation data location. Do you know where the measurements came from and if they're relevant to you?
<p>
What about data currency?
<p>
For example, if you can see the Sun, you can count the number of sunspots since that data comes from physically looking at the Sun. Mind you, can someone count the number of sunspots at night? It's not a trick question. The Sun isn't overhead for everyone all the time, and the data from any particular observer will be out of date at night. When was the count updated? Is it still actually current, let alone real-time? Obviously, not everyone uses the same data source either.
<p>
In case you're wondering, why are we counting by eye in the space age? It turns out that, since Galileo more than 400 years ago, it's the most long-term, reliable way to keep data consistent between observers and instruments, both of which often last only one or a few solar cycles, and it's also cheap!
<p>
What about equipment changes and failures in data gathering?
<p>
Geomagnetic activity isn't global; it's measured using a device called a flux-gate magnetometer. Measurements from specific instruments scattered around the globe are combined into the planetary, or Kp index. You'll discover that locations used change over time, and when instruments are down, the numbers are estimated, but you won't see that unless you actually find and explore the source data.
<p>
It's not just solarham.net and spaceweatherlive.com; it's pretty much every single site that shows any form of HF propagation or space weather information. Even sites based in a specific country, like the Australian Space Weather Service, have many instruments scattered around Australia. If you happen to be near an actual instrument, where "near" is anything less than 500 km away, how do you know if that instrument was actually online when a measurement was made?
<p>
Even if the instrument near you is working, is the data relevant to the receiving station on the other side of the planet?
<p>
If you look closely at the sites giving out current HF conditions, you'll discover that most of these don't even tell you where the data comes from, let alone if any of it was estimated to come up with their current reported values or recommendations.
<p>
If you start searching for historical information, this problem gets bigger. You'll find many sites that claim to have data, but are invariably underfunded, are rife with broken links, out-of-date servers, and moved, deleted, and abandoned pages. If you unearth a dataset, you'll discover that everyone uses a different standard to record their measurements.
<p>
How do you even know if combined measurements are coming from the right column? Think I'm kidding? There are documents with warnings about different formats, calculations, and dates on which these changed. Aggregating this data is challenging, at best.
<p>
So, is there a better way?
<p>
Yup. You're not going to like it. "Get on-air and make noise!"
<p>
I can hear you groaning from here. It's not all bad. You can run your own beacon to see the conditions at your location. It's what started me down the path of installing a WSPR, or Weak Signal Propagation Reporter, beacon and leaving it running 24/7. Currently, I'm focused on very weak, 10 mW signals. So far, it's been reported 3,685 km away.
<p>
If you visit the VOACAP or Voice of America Coverage Analysis Program website, you'll find a visualisation of how FT8 propagation worked between ITU zones between 2017 and 2019. It's not current, but it's an excellent way to see how propagation data can be derived from actual contacts.
<p>
What we really need are more beacon transmitters and online receivers.
<p>
I'm Onno VK6FLAB.
Listen:
What's the weakest signal that WSPR can decode?
Foundations of Amateur Radio
<p>
In 2016, Daniel EA4GPZ, documented how to discover the weakest signal that could be decoded using several weak signal modes, including WSPR, or Weak Signal Propagation Reporter. This is an interesting question because as you might recall, I've been experimenting with very weak signals coming from my shack. To date, my 20 milliwatts has been heard over 13 thousand kilometres away.
<p>
When you tune to a weak station you'll often hear both the station or desired signal as well as interference or background noise. The stronger the signal, the less noise you perceive. The weaker the signal, the more noise. You can express the relationship between the power of these two, the signal and the noise, as a ratio. If the power levels are the same, the so-called signal to noise ratio or SNR is 1:1. A higher ratio, like 2:1, indicates that the power of the signal is higher than the noise and a lower ratio, like 1:2 indicates that the signal is lower than the noise.
<p>
If you express this ratio in decibels, you'll end up with positive numbers where the signal is stronger than the noise and negative numbers where the signal is weaker than the noise and zero when they're the same. If I tell you that the signal report for my WSPR decode from Denmark was -28 dB, it means that the noise was much stronger than the signal.
<p>
For today I'm going to leave alone just how WSPR can report a negative signal to noise ratio and still successfully decode the signal, even though the signal appears to be buried in the noise.
<p>
That said, in this experiment, we're trying to learn something else. Using the technique detailed by Daniel, we test using different, known, signal to noise ratios to discover at what point the WSPR decoding process breaks down. This might help me understand if I can reduce my beacon output power even further and still anticipate a good chance of being decoded successfully.
<p>
To conduct his experiment, Daniel used the then current version of WSJT-X, version 1.7.0-rc1 and I'm using the current version today, 2.6.0-rc5 to repeat those tests. You might ask why I'm not taking Daniel's word for it and just using his findings. The process to decode a WSPR signal is all software and can be improved with better methodologies and algorithms. It's not unreasonable to think that in the years since Daniel's experiments things have changed, hopefully improved.
<p>
So, how does this work?
<p>
If you generate and attempt to decode one hundred different files, you can use the number of times that you count your callsign in the decode list as a percentage of success. If all of your files decode properly, the decode percentage is 100%. If only half of them are decoded successfully, it's 50% and so-on.
<p>
Similarly, if a different callsign, locator or signal power is decoded, you can count those as a percentage of false decodes. This is important because noise coming from the ionosphere can corrupt any signal. I should point out that because we know in advance what the decoded signal should be, since we created the message, we can actually count the ones that don't match what we sent. In the real world it's very hard, if not impossible, to do this, unless each transmitter also starts recording their efforts so data cleaning can be done after the fact.
<p>
A false decode happens when the software decodes a message and the result is not what was sent. Due to the way that WSPR works, this is not a case of a single character error and as a result the whole message is corrupt, wrong callsign, wrong grid square and wrong power level.
<p>
Just how prevalent this issue is, has to my knowledge so far not been discussed. Over the past year I've been working with the entire WSPR data set, nearly 5 billion reports, and mapping the data to explore just what's going on behind the scenes. Based on the raw data every single grid square on the planet has been activated. Of course this is not really the case, since there's plenty of parts on Earth where we haven't yet turned on a WSPR beacon.
<p>
Back to our experiment.
<p>
Two tools are used, "wsprsim" to generate an audio file and "wsprd" to decode it. Both come with WSJT-X and when you build the application from source, you get them as part of the process. The generator takes several parameters, one of which is the desired signal to noise ratio. If you ask it for a signal to noise ratio of -20 dB, wsprsim will generate the appropriate noise and the desired signal, combine them and build an audio file. You can then use wsprd to decode that file. If you repeat this many times, you end up with some data.
<p>
How many times?
<p>
Well, I probably went a little overboard. I generated a set for each SNR reading between 0 and minus 50 dB in 0.01 dB increments and then generated one hundred for each of those. At the point where the process broke down I doubled the resolution further to get a better idea of what was going on. About three quarters of a million tests. It took a while.
<p>
What did I learn from this?
<p>
First of all, false decodes happen at every signal level. I saw the first false decode at a signal to noise ratio of -0.07 dB. This is significant because it means that even at excellent signal levels there is a percentage of incorrect reports which explains why I'm seeing that result in real world data. When you start playing with really big numbers, even if the error rate is low, with enough data, it starts to matter. In my tests I saw an error rate of 0.03%. This means that there's at least 1.5 million false decodes in the current WSPR data set, likely more because wsprsim cannot emulate the real world of ionospheric and local noise.
<p>
On the flip-side, I also saw an overall success rate of nearly 94%. At -29 dB things start to change. Until then the decode is 100% successful, then it starts to decline to 0 at about -34 dB. Comparing Daniel's results directly, he saw 34% success at -30 dB, I'm seeing 95% at that same noise level. At -31 dB Daniel saw 6%, I'm seeing 75%. I don't see 34% until we get down to -31.6 dB and 6% at -32.4 dB. This indicates that the software has improved over the years.
<p>
It also means that with a signal report of -28 dB from Denmark, I've got a few dB to play with. I've now reduced my output power by another 3 dB, making it 10 mW. Point your antennas at VK6 and see what you can hear on 10m.
<p>
I'm Onno VK6FLAB
Listen:
One Volt ...
Foundations of Amateur Radio
<p>
Have you ever asked yourself a question that turned out to be a rabbit hole so deep you could spend a lifetime exploring and likely never come out the other end?
<p>
I did. Yesterday.
<p>
What's a Volt?
<p>
This came about when I started exploring how to measure the power output of my WSPR or Weak Signal Propagation Reporter beacon. According to the specifications the output level is 23 dBm or 200 milliwatts.
<p>
If you read the fine print, you'll discover that the power output actually varies a little depending on which band you're on, for my specific transmitter it says that the output on the 10m band is 22 dBm, or 158 mW.
<p>
That comes with a disclaimer, that there can be some variation on individual transmitters of about 1 dB. So, on 10m, my output could vary between 21 and 23 dBm, or between 125 and 200 mW. With my attenuator connected, the output could be between 12 and 20 mW, and that's assuming that my attenuator is exactly 10 dB, it's not.
<p>
Measuring anything means to compare it against something else. To give you a physical example. If you look at a tape measure, the distance between the marks is determined in the factory. The machine that prints the lines is configured to make the lines just so. In the factory there will be a specific master tool that determines how far apart the lines are in that factory. That tool is called "the standard". The process of lining up the standard with the machine making the lines is called "calibration".
<p>
If you build a house on your own with just that tape measure, everything should work out fine, but if you have a mate help you and they bring their own tape measure, from a different factory, their lines might not quite match yours and the fun begins.
<p>
If you don't believe me, as I've said previously, pull out all the tape measures and rulers around your house and see just how much variation there is.
<p>
In my house, well, my CNC, there's a standard that came with my micrometer kit. It specifies physically how long 25mm is. I also have a 50mm and a 75mm standard. When I compare the 75mm with the 50mm and 25mm together, they're the same within one hundredth of a millimetre. It's likely that it's better than that, but I'm still learning how to hold a micrometer and not have it overheat and stretch while I'm measuring. Yes, temperature changes the size of things.
<p>
The point is, in my CNC world, my current standard sits in my micrometer box. At some time in the future I might want to improve on that, but for now it's fine.
<p>
The standard that I have was at some point calibrated against another standard. That standard was in turn calibrated against another standard and so-on. Eventually you end up with an SI unit of 1 meter as defined by the International System of Units. In case you're wondering, it's defined as the length of the path travelled by light in vacuum during the time interval of one second. One second is defined in terms of the unperturbed ground-state hyperfine transition frequency of the caesium-133 atom. I know right, runs right off the tongue. I can't help myself, that frequency is 9,192,631,770 Hz.
<p>
Oh, this system is also subject to change. In 2019 four of the seven SI base units were redefined in terms of natural physical constants, rather than relying on a human artefact like the standard kilogram. This is an ongoing process. For example, in 1960, the meter was redefined as a certain number of wavelengths instead of a physical bar in a vault in Paris and there was also not just one bar, there were 30. National Prototype Metre Bar no. 27 made in 1889 was given to the United States and served as the standard for defining all units of lengths in the US between 1893 and 1960 - yes, perhaps surprisingly, the USA is metric, really. One inch used to be defined as "three grains of barley, dry and round, placed end to end lengthwise" but since 1959 is defined as exactly 2.54 centimetres or 0.0254 meters.
<p>
Back to power output on my beacon transmitter. Assuming for a moment that I had an actual tool available to measure this, I'd still be comparing my tool against another standard.
<p>
Let's imagine that I could measure the power output of my beacon with an oscilloscope. When the oscilloscope says 1 Volt per division. How do I know that it really is? If you start reading the calibration steps, you'll discover that they state that you need to connect your scope to a reference, another word for standard, and that's if you're lucky. Some documents just wave their hands in the air and say something like "push the auto calibrate button".
<p>
The Volt is defined as the electric potential between two points of a conducting wire when an electric current of one Ampere dissipates one Watt of power between those points. The Ampere definition involves counting elementary charges moving in a second. It's in the order of a 10 with 19 zeros. Not to mention that there's also a definition of how much an elementary charge is. You get the point, this is a rabbit hole.
<p>
So, now let's pretend that I have a calibrated oscilloscope. Let's say that our oscilloscope is calibrated within 1 dB. Cool. So I plug in my beacon and measure, what?
<p>
I'll end up with a reading, that's plus or minus 1 dB of "reality". In my case, perhaps I read 22.5 dBm. That means that it could be as low as 21.5 dBm or as high as 23.5 dBm, or between 141 and 224 mW. So, it's within specifications, great, but I don't actually know what the actual output power is.
<p>
Another way to look at this is to use a measurement to determine if the power is within specification or not. I'm guessing that Harry already did that test before he put my beacon in the box and shipped it to me.
<p>
Long story short, I'm no closer to knowing just how much power is coming out of my beacon, but I'm still working on finding a friend with a calibrated tool that might give me something a little more precise than fail or pass.
<p>
You know that there's a saying about turtles all the way down? I think it's rabbits myself.
<p>
I'm Onno VK6FLAB
Listen:
Which way did it go?
Foundations of Amateur Radio
<p>
Propagation, the art of getting a radio signal from one side of the globe to the other, is a funny thing. As you might know, I've been experimenting with WSPR or Weak Signal Propagation Reporter and for about a year running a beacon on 10m. Out of the box my beacon uses 200 mW to make itself heard. I couldn't leave well enough alone and I reduced the output power. Currently a 10 dB attenuator is connected to the beacon, reducing output to a notional 20 mW. I say notional, since I haven't actually measured it, yet.
<p>
With so little power going out to my vertical antenna, a homebrew 40m helical whip, built by Walter VK6BCP (SK), and tuned to 10m with an SG-237, it's interesting to discover what's possible.
<p>
Last night my signal was heard in Denmark. Picked up by Jorgen OZ7IT, 13,612 km away. That report broke another personal best for me, achieving 680,600 kilometres per Watt. I was stoked!
<p>
I shared a screen-shot of my report with friends. One friend, Allen VK6XL, asked a very interesting question. "What makes you think it was short path?"
<p>
Before I go into exploring that question, I need to explain. If I was to fly from Perth to Sydney, the popular way to travel is across the Australian Bight, over Truro, north of Adelaide, clip the northern tip of Victoria, over the Blue Mountains to Sydney. The distance is about 3,284 km. This route is known as the great circle route, more specifically, the short great circle route.
<p>
It's not the only way to travel.
<p>
Instead of heading East out of Perth, if I head West, I'd fly out over the Indian Ocean, Africa, the Atlantic Ocean, the Americas, the Pacific Ocean and finally arrive at Sydney. That journey would also follow a great circle route, the long great circle route. It's about 37,000 km long. You might notice that I wasn't very specific with either the path or distance. There's a reason for that. None of the tools I've found actually provide that information, other than to point out that the entire circumference of the planet is about 40,000 km and that it's not uniform since Earth isn't a perfect sphere.
<p>
You might be asking yourself at this point why I'm spending so much energy worrying about taking the long way around and how that relates to my 20 mW WSPR beacon.
<p>
In amateur radio we refer to these two travel directions as the short-path and the long-path.
<p>
Radio signals travel along the curvature of Earth bouncing between the Ionosphere and the surface. How that works exactly is a whole different topic, but for the moment it's fine to imagine a radio signal skipping like a stone on water. As a stone skips a couple of things happen. If the angle at which it hits the water is just right, it will continue on its journey, get the angle wrong and you hear "plop". Every skip is slightly lower than the previous because the stone is losing a little bit of energy. Every time the stone touches the water it creates a splash that ripples out in a circle from the place where the rock hit. These ripples also get weaker as they increase in diameter. Consider what happens if you skip a rock across concrete or sand instead of water and if you really want to geek out, there's also wind resistance on the rock.
<p>
A complex equivalent dance affects a radio signal when it propagates between two stations. For success, enough radio energy needs to reach the receiver for it to be decoded. For our signal to make it to the other side of the globe it must bounce between the Ionosphere and Earth's surface. Every bounce gets it closer to the destination. Each time it loses a little bit of energy. This loss happens at the Ionosphere, at the surface and in between through the atmosphere.
<p>
To give you a sense of scale, my signal report from Jorgen in Denmark was -28 dB. It started here in Perth as 13 dB, so we lost 41 dB along the way. We're talking microwatts here. I'll note that I'm avoiding how this is exactly calculated, mainly because I'm still attempting to understand how a WSPR signal report actually works since it's based on a 2,5 kHz audio signal.
<p>
As I said, enough energy needs to make it to the receiver for any of this to work.
<p>
There's an assumption that less distance means less energy loss. It's logical. A shorter distance requires less hops and as each hop represents a specific loss, less hops means less loss.
<p>
But is that really true?
<p>
There's nothing stopping my beacon signal from taking a different route. Instead of travelling the short-path, it can just as easily head out in the opposite direction. Theoretically at least, my vertical antenna radiates equally in all directions. The long-path is mostly across water between Perth and Denmark. What if hops across the ocean were different than hops across a landmass? Turns out that they are in several ways. For example, there's less energy loss in a refraction across the ocean, how much less exactly is still being hotly debated. Much of the data is empirical at the moment.
<p>
It gets better.
<p>
What if I told you that the report was near to sunset? At that time there's a so-called grey line phenomenon related to how the sun stops exciting the Ionosphere and how different layers of the Ionosphere start merging. As a result the angles of refraction across the Ionosphere change and longer hops are possible.
<p>
What if the long-path took less energy to get to Denmark than the short-path did?
<p>
Would Jorgen's decoder care?
<p>
If that's the case, my signal didn't travel 13,612 km, it travelled twice that and I'd have well and truly cracked a million kilometres per Watt.
<p>
So, is there a way we could know for sure?
<p>
Well, yes and no.
<p>
For starters we'd need beacons that transmit at a very precise time. Then we'd need synchronised receivers to decode the signal. A signal travels 3,000 km in a millisecond, so we're going to need something more precise than the timing set by NTP or the Network Time Protocol used by your home computer. If we used GPS locked transmitters and receivers we'd be working in the order of 50 nanoseconds and be in the range of 15m accuracy.
<p>
That would allow us to calculate the physical distance a signal travelled, but that's not the whole story.
<p>
What happens if your signal travels all the way around the globe, or if some of it reflects back, so called back scatter, like the ripples from a stone coming back towards you, and that signal travelling back past you to the receiver? There's endless variation, since the planet isn't round with a flat surface nor is the Ionosphere.
<p>
So, do we know if my report was a long-path or a short-path? Not really. Based on the time of day, there's a good chance that it was a long-path report, but only if we actually measure the delay between send and receive will we have data to make a better assurance than "possibly" or "probably".
<p>
As I started, propagation is an art.
<p>
I'm Onno VK6FLAB
Listen:
Morse is dead ... long live Morse!
Foundations of Amateur Radio
<p>
One of the oldest means of electronic messaging is Morse code. Developed by Alfred Vail and Samuel Morse and sent for the first time on the 24th of May 1844, Morse code changed the way we communicate.
<p>
For nearly a century it was required to become a licensed radio amateur until in 2003, the International Telecommunications Union or ITU left it to the discretion of individual countries to decide if a budding amateur needed to demonstrate their ability to send and receive in Morse. With that decision many thought that the end of Morse code was only a matter of time.
<p>
They were wrong.
<p>
Turns out that use and progress of Morse code continues at a surprising rate. Searching for scholarly articles on the subject, you'll discover that it's used, for communication by quadriplegics, for information exchange between IoT or Internet of Things devices, as a way to secure information combining DNA and Morse code, as a method for gesture recognition, as a research tool for psychologists interested in learning methodologies, for training neural nets, for REM sleep research and plenty more.
<p>
Learning the code is an activity that sparks joy or dread, depending on whom you ask. For me it's been a decade of anticipation with little to show for it.
<p>
How to learn is a question that prompts as many answers as there are people within earshot and most of those disagree with each other. If you do ask, you'll discover that there are dozens of websites that offer to teach you, podcasts and audio files, bits of paper, buzzers, software and video, images and cheat sheets, the list is endless. You'll also discover two terms, Koch and Farnsworth. Both are intended means of learning. You'll find proponents of both methods wherever you look. You'll also hear from people who learnt the Army way, whatever that means, there's people who were taught not to send before they could properly receive, those who were taught the opposite and everything in between.
<p>
There's discussion on the topic, heated even, but very little in the way of actual hard data. There's some research. In 1990 the Keller Method from World War 2 was explored. The method involves playing a Morse letter, followed by a gap where the student is expected to write the letter, followed by a voice prompt of the letter. Interesting, were it not for the fact that it looked at nine students and only at their ability to master the alphabet.
<p>
In 1960, 310 airmen were subjected to 14 tests to determine their ability to learn Morse. No idea what the research outcomes were, since the Journal of Applied Psychology doesn't appear to share their research unless you pay for it.
<p>
There are reports of actual science behind the Koch method of learning, but I wasn't able to find it, though it's repeated often. It's only with the introduction of computers that actually using this method of learning has become practicable and recently popular.
<p>
As you might know, I've been attempting to learn Morse code for a while now. I've tried many different things, including Farnsworth, Koch and others. I publish versions of my podcast as Morse code audio only. They're published every week and there are a few people who listen.
<p>
I also attempted to make stereo audio files with a computer generated voice in one ear and a Morse word in the other, I generated flash cards, I tried learning the code as dits and dahs, but in the end, nothing really worked for me.
<p>
About a month ago I came across a video on YouTube by Electronic Notes. It contained the Morse alphabet as audio and flashed the letter visually on the screen whilst the audio was playing. There's also a video with numbers and a combination of the two.
<p>
It gave me the idea for something entirely different to try and in preparing to talk about this, it turns out that there's even research to suggest that I might be on to something. I discovered that in 1994, sixty healthy people were tested to determine if learning Morse code in a rehabilitation setting was best achieved using visual, auditory or a combination of both. The research conclusion was that the combination works best.
<p>
My idea is a video that shows an individual word whilst Morse code for that word is heard. There's no dits and dahs on the screen, just the word, written in English, and the Morse code for the word. The speed is 25 Words Per Minute, or WPM, and it's played with a side-tone of 600 Hz. Each video is an entire podcast, lasts about 30 minutes, and plays at full speed.
<p>
I'm already beginning to notice that some words sound like a sound blob in much the same way as when I learnt a new language, so I'm hopeful that this will finally get me on my way.
<p>
It's early days and the video channel is an experiment, so please comment to share your thoughts on the experience.
<p>
Who knows, I might have introduced a new way to learn.
<p>
Now all we need is some research to compare it to other methods, Koch, Keller, Farnsworth and Onno, hi hi.
<p>
You'll be able to find this article on YouTube too, "Morse is dead ... long live Morse!"
<p>
I'm Onno VK6FLAB
Listen:
Attenuators, the missing link...
Foundations of Amateur Radio
<p>
Having been able to call myself an amateur for over a decade, it might come as a surprise to you that it wasn't until a couple of weeks ago that I thought about attenuators for the first time. They're a curious tool and once you come across them, you'll never be quite the same.
<p>
Before I dive in you should know that an amplifier is an active tool that makes things bigger and an attenuator is a passive tool that makes things smaller. To look at, attenuators are diminutive to say the least. The ones I have in my kit look like barrel connectors, a male and female connector and seemingly not much else, but looks can be deceiving and I'll mention that shape isn't universal.
<p>
The purpose of an attenuator is to reduce the power of an RF signal by a known amount, preferably without distortion or any impedance mismatches. When you go out hunting and gathering, your choice of connector is the first obvious selection, but soon after you'll be asked for a frequency range, an impedance, a power level and an attenuation level, so let's take a look.
<p>
I have some attenuators with N-type and SMA connectors. There's options for every connector under the sun, so consider what you're using with your gear and remember to think about your measuring equipment connectors as well. In my case my shack is pretty much SMA the whole way, but a friend had some broadcast N-type attenuators and I was unable to resist.
<p>
The next thing is impedance. In my case 50 Ohm, but there's options for other choices like 75 Ohm for TV based attenuators.
<p>
The purpose of an attenuator is to reduce power. It does so by converting power into heat and more power handling means more heat. Too much heat and the attenuator starts letting out the magic smoke, so consider how much power your RF source is generating. Putting out 5 Watts? Then make sure that you don't connect a 1 Watt attenuator to that radio.
<p>
Now for the attenuation level. It's described in dB or decibel. At first the numbers look bewildering, but pretty soon you'll be familiar with how it hangs together. A 3 dB attenuator will halve the signal, so a 10 Watt signal will be reduced to 5 Watts and a 200 mW signal will be reduced to 100 mW.
<p>
If you have a 6 dB attenuator, it will halve again, so 10 Watts becomes 2.5 Watts and 200 mW becomes 50 mW.
<p>
A 10 dB attenuator is a little more than 9 dB, so you could try something along the lines of a bit more than half again, but you don't need to. 10 dB attenuation is essentially moving the decimal point. A 10 Watt signal with 10 dB attenuation becomes 1 Watt. A 200 mW signal becomes 20 mW.
<p>
If you have a 20 dB attenuator, it moves the decimal point two places, 10 Watts becomes 0.1 of a Watt, or 100 mW and 200 mW with 20 dB attenuation becomes 2 mW. You can connect two attenuators together and combine their values by adding them together. For example, combining a 10 dB attenuator with a 3 dB attenuator makes for 13 dB attenuation which moves the decimal point and then halves that.
<p>
All that's fine and dandy, but what's the point?
<p>
Well, imagine that you want to measure the actual power output of your radio. If you were to pump the minimum power level of my Yaesu FT-857d into a NanoVNA you'd blow it up, but if you added say 20 dB attenuation, that 5 Watt would become 0.05 Watts or 50 mW which is half the power rating of the NanoVNA. If you're not confident that your radio is actually putting out 5 Watts, you could add 30 dB attenuation and have a safe margin at an expected output of 5 mW.
<p>
I mentioned that attenuators don't all look like an innocent barrel connector. That's because if you have to attenuate something with higher power levels, you'll need a way to dissipate heat, in much the same way as a dummy load has cooling fins, higher power attenuators can come with cooling fins too.
<p>
On the inside of this contraption is a simple circuit made from three or four resistors which combine to attenuate your signal. If you're inclined to build your own, there are plenty of online calculators to be found that show how to put an attenuator together.
<p>
One thing I've skipped over is the frequency range. Most of us are having fun with HF, VHF and UHF, generally below 1 GHz, so most attenuators will be fine, but if you are playing at higher frequencies you should take note of the frequency range specified for the attenuator.
<p>
While on the subject of frequency range. You can easily measure the actual performance of an attenuator using a NanoVNA. Connect Port 1 to Port 2 through your attenuator and using the magnitude trace you can see just how much attenuation it provides. Be sure to set the intended frequency range and calibrate without the attenuator before measuring.
<p>
Now that I know about attenuation, I cannot imagine a life without, but to be fair, I was in blissful ignorance for more than a decade, so this might not apply to you, yet, but one day perhaps you'll find yourself thinking about adding some attenuation to your tool kit.
<p>
I'm Onno VK6FLAB
Listen:
How low can you go?
Foundations of Amateur Radio
<p>
It's common knowledge that power, as in output power, makes your signal heard in more places. If you've followed my adventures you'll also know that I'm a firm believer in low power or QRP operation.
<p>
It all started when I was told that my shiny new amateur license was rubbish because I was only allowed to use 10 Watts. Seemingly the whole community around me shared that opinion and slogans like "life's too short for QRP" are still commonly heard.
<p>
As a direct result of that sentiment I decided to explore and document just how much I could actually do with my so-called introductory license, the Australian Foundation License. I've now held it for over a decade and I'm still exploring and writing.
<p>
One of my first acts of rebellion was to lower my radio output power to its minimum setting of 5 Watts and half legal power was sufficient to prove my point.
<p>
Although I'm still regularly being encouraged to upgrade, my second act of defiance is to keep my Foundation License until I decide that I need more. I'll let you know if it ever happens.
<p>
One more well known so-called "fact" about our hobby is that if you use low power you'll really only get anywhere on the higher bands, 2m, 70cm and above. There's plenty of reports of amateurs using a low power handheld radio to talk to the International Space Station and my own satellite internet used 1 Watt to get to geostationary orbit. On HF on the other hand, 5 Watts is as low as you really want to go. Making contacts is a struggle and often frustrating, but when you do, bliss!
<p>
About a year ago I took delivery of a WSPR beacon. It's capable of transmitting on all my accessible HF bands using 200 mW. Given my antenna situation I've configured it to transmit on the 10m band, 24 hours a day, thunderstorms excepted. When making the purchase decision I had no insight into how my beacon would perform. 200 mW is stretching even my love of low power, but I hooked it up and turned it on and waited.
<p>
It came as quite a surprise that my beacon was heard over 15 thousand kilometres away, not once, not a couple of times, but regularly. When I came up with my November challenge to see if I could improve on that I made an almost throw away comment about reducing power to see if I could still make the distance.
<p>
A couple of weeks ago I hooked up a 6 dB attenuator to my beacon, reducing the power from 200 down to 50 mW. It came as quite a surprise that my signal made it to the same receiver in the Canary Islands. My kilometre per Watt calculation shot up, quadrupling my previous record.
<p>
Just imagine, 50 mW making its way over a third of the way around the globe, bouncing between the ionosphere and the planet, just like any other HF signal. At that point I realised I had learnt a few things. You don't need stupid power to make a distant contact on HF either. I started wondering just how little power was needed to get out of the shack.
<p>
Yesterday I hooked up a 10 dB attenuator and within ten hours my now 20 mW beacon broke my own kilometre per Watt record again and based on the signal to noise numbers from previous contacts, I see no reason for that record to stand for very long. Once that happens I've got plenty more attenuators to play with and I'm not afraid to use them.
<p>
Now I'm on the hunt for an attenuator that will reduce my main radio output from 5 Watts. I'm told I should aim for double the power rating, but I also have to consider how to connect my antenna coupler which needs 10 Watts to tune, but that's a project for another day
<p>
When was the last time that you used really low power?
<p>
I'm Onno VK6FLAB
Listen:
The nature of learning things...
Foundations of Amateur Radio
<p>
Recently I discussed the concept of a VFO, a Variable Frequency Oscillator. It's an essential building block for our amateur radio community. In describing the idea behind it, while making an error in one of the CB radio frequencies, thanks to Ben VK6NCB for picking that up, I skirted around how a VFO actually works.
<p>
In reality the VFO is a collective term that describes a whole range of different methods to vary a frequency. Naturally I continued my exploration and discovered a whole range of documentation on the subject. I even started writing about how one common method, a Phase Locked Loop or PLL, works and how a VCO, a Voltage Controlled Oscillator, operates as part of that. I'll come back to those shortly.
<p>
In doing my reading, since, as is often the case, I use my weekly contribution to the world as a method to learn things. I'll investigate a topic and attempt to describe who came up with it, what it means, how it works and what its place is in the world, the who, where, why and what of it, if you like. I suspect that comes from my very first introduction to broadcast radio where that was one of the very first things I was taught, thirty years or so ago.
<p>
If you've followed along for the decade I've been at this you'll know that I also intersperse such learning with observations about the things that I'm interested in. This is such an observation, a meta view if you will.
<p>
I discovered somewhat to my chagrin that the ways that an essential component of our hobby, a system called a Phase Locked Loop, was described in such academic terms, complete with formulas and detailed circuits and even component lists, spread over pages and pages of verbiage, or explained in YouTube videos lasting an hour or more. Of course there were some little gems, ElectronicNotes on YouTube manages to cover the basics in little over six minutes, but that's a rare example.
<p>
It reminded me of a website that I've been using to fill in the gaps in my understanding of SDR or Software Defined Radio and Digital Signal Processing or DSP. The PySDR.org site is an online textbook written by Dr. Marc Lichtman. He says about his method: "Instead of burying ourselves in equations, an abundance of images and animations are used to help convey the concepts [...]"
<p>
My weekly efforts have always attempted to do exactly that and I found myself in a place where such a thing didn't appear to exist for the concepts behind the PLL and VCO. My obvious response to that would be to write the missing document and as I said, I have a first draft of it sitting on my computer.
<p>
There's only one problem.
<p>
I don't yet "grok" the concepts. If you're unfamiliar with what grokking is, it means to understand intuitively and emphatically. It also means that unless I can describe it in less than a single page of A4 paper I don't understand what I'm saying and you'll get bored waiting for me to make a point.
<p>
Here's my point.
<p>
How do you learn concepts? What is it that you do to discover new topics of interest and how do you progress through the various stages between discovery and grokking?
<p>
For me it's about puzzle pieces. It's always been puzzle pieces. Little nuggets of information, almost trivial on their own, but after a while you get to a point where you have enough of them that you can start joining them together to grasp a more complex concept.
<p>
Here's a puzzle piece I discovered today.
<p>
Impedance: The difference between an explosion in air and one under water is impedance.
<p>
It's little concepts like that which make me get out of bed and discover what's on the horizon next. I'm also learning about double and triple conversion superheterodyne radio which I believe has a one-on-one parallel application in Software Defined Radio and Digital Signal Processing. Once I figure out how to describe it to you, I'll let you know.
<p>
The point of all this is that learning things is as much about understanding as it is about explaining.
<p>
Feel free to point me at new and interesting basic concepts.
<p>
I'm Onno VK6FLAB
Listen:
What's in a VFO?
Foundations of Amateur Radio
<p>
One of the many acronyms that define the world of amateur radio is VFO. It stands for Variable Frequency Oscillator. That doesn't explain much if you're not familiar with the purpose of it and just how special this aspect of amateur radio is.
<p>
Much of the world of radio beyond our hobby, like broadcast television, WiFi and Citizen Band or CB, to name a few, uses radio spectrum in a particular way. On a television you change channels to switch between stations. Similarly, a WiFi network uses specific channels to make your wireless network a reality and the same goes for CB, different channels to make yourself heard.
<p>
Looking specifically at CB for a moment, if you look at channel 8 for example, depending on which type of equipment you have, your radio might be using 27.055 MHz, or 476.575 MHz, or 476.6 MHz. Each of those frequencies can be described as CB channel 8. The first is on the 27 MHz or 11m band, the second is if you're using a 40 channel radio, which is now depreciated and the third is if you're using an 80 channel radio.
<p>
If you look at digital broadcast television, channel 8 is on 191.5 MHz. On WiFi, channel 8 is on 2.447 GHz or 5.040 GHz.
<p>
You get the point, depending on where you are as a user of radio spectrum, channel 8 might mean a whole host of different things and as I've described with CB radio, that might even change over time.
<p>
Harry Potter needed magic to reach Platform Nine and Three-Quarters at Kings Cross Station to get to school. In a channelised world, getting to an in-between frequency is not possible if you're using licensed equipment, unless you're a radio amateur, then you can use magic to get into the gaps. That magic is called the VFO.
<p>
You might recall that our radios use many different frequencies internally to be able to filter out specifically what signal you want to hear. Most of those frequencies are fixed, in fact in the vast majority of cases these are actually tuned and calibrated to work in a very specific way.
<p>
The one exception is the VFO, it's by nature variable. It's likely calibrated, but it's not fixed and that allows our community to tune our equipment to any frequency we desire.
<p>
The traditional user interface for this is a big knob on the front of your radio, colloquially referred to as the dial, as-in turn the dial to change frequency.
<p>
This allows us something quite rare in radio land. We can be frequency agile. It means that if there's interference at a specific frequency, we can tweak our VFO and slightly modify where our radio is tuned. You use this almost subconsciously when you're on HF trying to tune to a particular station.
<p>
In the world of software radio there's likely no knob. You type in a number and the variable frequency oscillator in the radio is tuned to another frequency and the output signal, or transmit signal if you're making noise on-air, changes to another frequency.
<p>
Digital modes like WSPR, which generally use a very specific frequency also vary that frequency but in a different way. You set your radio to the appropriate so-called dial frequency, let's say 28.1246 MHz on the 10m band and then the software alters the signal by up to 200 Hz to change within the available audio range of your radio, altering between a low of 1400 Hz and a high of 1600 Hz, making the actual WSPR frequency on 10m between 28.1260 and 28.1262 MHz.
<p>
I'm mentioning the WSPR example because while we're frequency agile in our hobby, we do use channels as well. There's a specific set of frequencies set aside, channels if you like, for WSPR, FT8 and other modes. We do the same on the 2m and 70cm bands where we have rules for where repeaters are allowed to be.
<p>
It means that we get the best of both worlds. We have the stability and institutional knowledge where repeaters or some modes go, but we also get to play in any spot we want.
<p>
For example, there's nothing stopping me and a friend setting our radio to some random frequency within our license allocation and outside pre-allocated space and run a WSPR transmitter there. Only the two of us will know about it, well at least at first, but it allows us to experiment away from any other users who might experience interference from our tests and exploration.
<p>
The VFO is what makes our hobby so very interesting and it's what makes it possible to do weird and wonderful experiments.
<p>
I'm Onno VK6FLAB
Listen:
My Virtual Workbench
Foundations of Amateur Radio
<p>
With the ever increasing pace of innovation, well, change, I'll leave alone if it's actual innovation instead of marketing, we see new software released at an almost alarming rate.
<p>
There is an urge to stay abreast of this process, to update, upgrade and try new solutions as soon as they are presented to you by well meaning friends and colleagues, not to mention online marketing, uh, reviews and other enticements that make you click the button to install something to avert the fear of missing out.
<p>
If you've done this for a number of years, actually, who am I kidding, a number of weeks, you'll discover that this comes at a cost. One that the corporate world has attempted to address by using terms like Standard Operating Environment, backups, administrator privileges and other such annoying things that prevent users from trying something new and breaking things.
<p>
At home and in the shack most of that is not a problem. No corporate IT division around to stop you, but soon you'll discover that something you installed caused you grief, encouraged your logging software to stop talking to your radio, prevented you radio from changing frequency, or blocked the latest digital mode from working as intended.
<p>
I live in that world too, but with the benefit of an IT background I decided nearly a decade and a half ago that enough was enough. I bit the bullet and bought myself a new computer. I vowed to install only one tool on that laptop, a virtualisation environment, also known as a hypervisor. It allows you to run a virtual computer inside a window. Given enough CPU power you can run multiple virtual computers in multiple windows inside your actual physical hardware.
<p>
This gives you flexibility. You can run a copy of your favourite operating system in a virtual environment, install the latest and greatest software on it and if it breaks, you delete it and start again. In my case I'm running my daily desktop environment where I'm currently writing this as a virtual Linux machine inside my physical computer which is also running several other virtual machines, including some network monitoring tools, a software defined radio development environment, my accounting software and plenty of other things.
<p>
Each virtual machine is nothing more than a folder on my physical computer and making a full backup is as simple as making a copy of that folder. Better still, if I want to try a new version of something on a machine that I'm already using, I can duplicate the folder, fire up the copy of the virtual machine, install the new software and test it. If it works, great, if not, throw it away and start again.
<p>
Changing physical computers is also simple. Buy a new computer. Install the hypervisor, copy the machine folders across and start working.
<p>
From a security perspective, it also means that I can install a random bit of software recommended by a friend without getting worried about it stealing any of my information, given that my private information isn't on the virtual machine on which I'm installing this unknown piece of software.
<p>
I also use this to compile new bits of code. If I come across a project on GitHub that I'd like to try, I can fire up a brand new machine and install all the prerequisites without running the risk of breaking something that I rely on. It also means that I can test with different operating systems, from macOS, any flavour of Linux, copies of Windows and play with virtual copies of Android or if I'm feeling frisky, BeOS.
<p>
There are other ways to achieve some of this. For example, you could get yourself a Raspberry Pi and half a dozen MicroSD cards. Install an operating system onto a card, boot the Pi, install your new application and if you like it, use it. If not, wipe the card, start again. You can have a dedicated WSPR beacon card, a contest logging card, whatever you need, all separate, all easy to backup and change as needed.
<p>
If that's not enough, some virtualisation environments allow you to emulate different microprocessors, so you could run ARM code on an x86 processor, or vice-versa.
<p>
If you want more, you can investigate containerisation. A tool that allows you to essentially create a mini virtual machine and run a new environment using a single command, so fast that you essentially don't need to wait for it to start-up, allowing you to mix and match environments as needed.
<p>
At this point you might ask why I'm even talking about this. What does this have to do with amateur radio?
<p>
Well, it's how I have my test bench set-up. Sure I have a soldering station, multimeters, a NanoVNA, an antenna analyser and all that kind of great stuff, but my radio world is mostly software and in that space all my tooling is pretty much virtual, put together in such a way that I can pick and choose precisely how I want to test something without killing something I rely on.
<p>
I'm telling you about it because in my experience much of the amateur community still relies on a desktop computer running Windows and I have to tell you, there is so much more out there for you to explore.
<p>
What does your virtual workbench look like?
<p>
I'm Onno VK6FLAB
Listen:
A plan for distributed SDR decoding
Foundations of Amateur Radio
<p>
Yesterday I finally discovered the missing piece of information that will allow me to create a project that I've, if not outright spoken about, at least hinted at.
<p>
In an ideal world by now I'd have built a proof concept and would be telling you that I've published a GitHub repository under my callsign for you to explore. If wishing made it so. Unfortunately, currently sitting at a keyboard for anything longer than ten minutes or so makes it nigh on impossible to stand up, so you'll have to make do with hand waving and gesticulation rather than actual code, but for now, that's all I have. Consider this a design specification if you're so inclined.
<p>
So, big idea.
<p>
Imagine that you have a device that can listen to radio frequencies. This device is connected to a network and it shares the data to any number of different listeners which might each do something different with the information.
<p>
If you were to do this in the way we watch YouTube or listen to streaming audio, each listener would get their own unique copy of the data. If you have ten listeners, you'd have ten streams crossing your network, even if everyone was enjoying the exact same video or audio at the exact same time.
<p>
Instead I want the data coming from the device to have only one stream on the network and for as many different listeners or clients to access it as required at the same time.
<p>
Let's get specific here for a moment. I'm talking about using a software defined radio, could be a $25 RTL dongle, could be any SDR, that is tuned to a part of the spectrum, let's say the entire 40m band, and sends that radio information digitally onto the network. This network could be your local network, or it could theoretically be the internet, for now, let's just put it out on our own network.
<p>
So, you have a copy of the entire 40m band streaming across your network. Great, now what? Well imagine that you want to decode RTTY on 7.040. You fire up your decoder, point it at the network stream and decode RTTY.
<p>
Then you want to decode a WSPR signal, at 7.0386. You fire up your WSPR decoder, point it at the network stream and decode WSPR.
<p>
Then you want to decode FT8 on 7.056, same deal, fire up your decoder, point it at the network stream and decode FT8.
<p>
Now you want to compare two different RTTY decoders. Fire them both up, point them both at the same stream, decode both, simultaneously.
<p>
Of course you could do this with CW signals, with SSB signals, with any decoder you have lying around, Olivia, Hellschreiber, AM, Packet, whatever. All these decoders could be running independently but together on the same band.
<p>
You could add a tool that shows a waterfall display of the same data on a web page, or play some of the decoded data to your headphones, or record it to disk, or do spectral analysis, all at the same time.
<p>
The information that you're processing is on the network once. You don't have to flood your network with multiple copies of the 40m band, the only limit is how much CPU power you can throw at this and to be frank, most computers on the globe today spend much of their time waiting for you to do something, so processing a bit of data like this is not going to tax anything built in the past 20 years or so.
<p>
The missing ingredient for this was a Linux tool called netcat, or nc. It allows us to distribute the information across the network using a technique called broadcasting.
<p>
So, RTL dongle, data extracted by a tool called rtl_sdr, distributed across the network using netcat and used by as many clients as you can think of.
<p>
The proof of concept I'm working on uses Docker to build a bunch of different containers, or clients if you like, that each can do a different task with the same stream. When I've got something to show and tell, you'll find it, predictably, on my GitHub page.
<p>
Oh, if you want to run the same thing for say the 80m band, you can. Now you have two network streams, one for 40m, one for 80m and as many decoders on your network as you have CPU cycles to play with.
<p>
If all this sounds like magic, you've seen nothing yet.
<p>
I'm Onno VK6FLAB
Listen:
The sedentary myth of radio.
Foundations of Amateur Radio
<p>
When people think about and discuss my chosen hobby, amateur radio, there's often a perception that it's old men sitting behind a radio tapping on a Morse key, making beeping noises surrounded by all manner of imposing equipment, stacked thick and high in a tiny room that soon becomes too stifling to spend much time in.
<p>
While such scenes might exist, often reinforced by old photos and messy radio shacks, any self respecting amateur will tell you that plenty of time is spent outside the shack dealing with antennas, coax and earthing systems, combined with pouring concrete, building, erecting and climbing towers and a myriad of other physical activity.
<p>
My experience has shown that my own inertia bending acts often involve things like camping, portable operation in ever changing environments, throwing ropes into trees and recovering those later, erecting verticals, tying down squid-poles and other muscular movements like building temporary rotators lashed to the nearest utility vehicle to take advantage of a multi-band yagi that someone brought along to play with during a field day.
<p>
The first time I really discovered just how lacking my stamina is, was in early 2014 when the FT5ZM DXpedition team to Amsterdam Island was in town. I had the pleasure of spending a day with a couple of team members showing off the sights of my QTH, Perth in Western Australia. In the middle of the city is Kings Park. To give you a sense of scale, at over 400 hectares, Perth's Kings Park is larger than New York's Central Park and London's Hyde Park. One of the attractions is the dual spiral staircase DNA tower. At 15m height, it's the highest viewing point in Kings Park offering 360 degree views of the park and the city surrounding it. Commissioned in 1966, the tower has 101 steps and has recently been refurbished. It derives its name from the DNA Double Helix molecule, which is how the staircases are arranged.
<p>
One of my companions on the climb to the top was a sprightly amateur who's been licensed a decade longer than I've been alive. I marvelled when Arnie N6HC essentially ran up the tower when all I was able to achieve was puff my way up in his wake.
<p>
Since then I've discovered that doing 24 hour contests, camping and other fun stuff now absolutely kicks the stuffing out of me, often requiring that I spend a day in a small dark room recovering with a blanket over my head. While my body shape and my callsign have things in common and my doctor continues to encourage me to lose weight, I can say that my recent visit to hospital, unexpected as it was, reminded me in no uncertain terms that I should look after myself, if only so I can actually participate in the next contest or camp-out.
<p>
I'm not going to tell you what my fitness plan is, nor am I going to tell you to embark on one of your own, other than to ask, have you considered just how much of this wonderful hobby goes beyond keying a microphone or tapping a keyboard and consider just how safe you really are when you next climb up a ladder, tower or other height to fix an antenna?
<p>
Speaking of health, I've been absolutely blown away by the incoming messages, offers of help, shared gallbladder emergency and post-operative experiences and more, from people whom I've known for years through to amateurs who took a chance to introduce themselves and wish me well. It wasn't until this week that I really understood that this community is rich in personal lived history, going well beyond the experiences I've had outside the hobby. I'm ever so grateful for your encouragement and intend to keep fighting to get well. It's going to take some time, but I'm looking forward to when I can next camp-out and not regret my life choices.
<p>
So, get off your sedentary and go do something will ya?
<p>
I'm Onno VK6FLAB
Listen:
Setting a little personal challenge ...
Foundations of Amateur Radio
<p>
A week ago I unexpectedly had my gallbladder removed. As emergencies go, I was lucky to be in a major metropolitan area with a remarkable hospital, supported by a group of humanity whom I've never much interacted with in my life. The staff at Sir Charles Gairdner Hospital were without exception amazing, from the orderlies to the nurses and everyone behind those, I interacted with about fifty people directly during my stay and every single person had a smile to share and an encouraging word to give. As life experiences go it was as uplifting as I've ever had the opportunity to celebrate. Sure it hurt like hell and there were things I'd rather not have to try again, but on the whole it was, if not pleasant, at least memorable. Recovery is going to take a little while and I understand my voice is expected to return to normal in a few weeks having been intubated for most of a day.
<p>
Half an hour after being discharged from my five days in hospital I was faced with a choice. Produce nothing for my weekly contribution to our hobby and face the risk of an astronomical bill from my hosting provider because the script that I wrote didn't foresee that there might be a time when I was unable to provide content, or produce something that, to be sure, was lacking in every way, but at least know that there wouldn't be a surprise waiting on my bank statement next month. So, my inadequate production saw the light of day. For that I apologise, it should have been silence.
<p>
During the week I returned to my shack and had a look at my beacon. As you might recall, I've been using Weak Signal Propagation Reports, or WSPR in my shack for a while. According to the logs the very first time was in November of 2017. At the end of last year I took delivery of a ZachTek desktop WSPR transmitter which has been reported on air over 16 thousand times since. I've only been using the 10m band and it's been heard as far away from me in Western Australia as the Canary Islands, the home of Johann EA8/DF4UE and Peter EA8BFK who between them reported my signal nearly 90 times. It's remarkable to note that this is a distance of over 15 thousand kilometres, on the 10m band, using only 200 mW.
<p>
During the week I made another milestone, a report in the opposite direction, across the Pacific Ocean to mainland USA. While that didn't break any distance records, it was a thrill to see a report from the Maritime Radio Historical Society, logging WSPR signals using KPH.
<p>
Other things to note about these reports are that its been heard across 81 different grid squares, by 144 different stations from all directions of the compass.
<p>
During my hospital stay and since, I've come to appreciate setting little goals. Little personal achievements that in and of themselves are not meaningful to anyone but me, and in some cases, my medical support team. It reminded me of a time when I attempted to achieve this in amateur radio, making a contact every day. Looking back over my logs I can tell you that I've not managed to maintain that, though, technically, on average, given that I host a weekly net and there's generally more than seven people who join in, I could claim an average of one QSO per day, but both you and I would know that I was stretching the truth somewhat.
<p>
It occurred to me that my signal report by KPH could be considered the beginning of my new 10m adventures. Much of my start in this hobby was during the previous solar cycle and the 10m band featured heavily in much of my activities, especially since you can get on that band with the very minimum of antenna, a quarter wave on 10m is a 2.5m whip and that can fit even on my car and it did, for years.
<p>
When the solar cycle eventually wound its way down, the 10m band was quiet for much of the year with the odd spot to whet your appetite, but rare enough to have little in the way of ongoing contacts.
<p>
As far as I'm concerned, 10m is back in play and it's my personal special band, so I'm setting myself a little challenge for the month of November and you can join in, open to anyone who wants to play. There's no prize, no scoreboard, no accolades, no nothing, other than the personal satisfaction of achievement.
<p>
Here's the challenge. How many kilometres per Watt can you achieve during November? To explain, my beacon uses 200 milliwatts, so any distance is multiplied by five to get the km/W number. If you use more than a Watt, you'll need to divide your distance by the number of Watts you use. As I said, this is a personal challenge. I'm not going to adjudicate, there's no rules to break, no one to tell you that you're cheating, it's just between you and your WSPR beacon.
<p>
For now, my record is 75630 km per Watt. I'm going to take the opportunity to consider what I might do to improve on that. Perhaps if I reduce power I'll still be heard in the Canary Islands, but I'll have more bang for my buck. Time will tell. Feel free to share your own achievement, or keep it to yourself, entirely up to you.
<p>
In case you're wondering about the capacitor thing, a gallbladder is like a bile capacitor, the analogy came from a story I wrote whilst in hospital, it might even see the light of day...
<p>
I'm Onno VK6FLAB
Listen:
This space left intentionally blank
Foundations of Amateur Radio
<p>
Forgive my briefness. You'll discover why this space was left intentionally blank next week. It involves a broken capacitor, of sorts.
<p>
<p>
I'm Onno VK6FLAB
Listen:
The Amateur's Code for future generations...
Foundations of Amateur Radio
<p>
Over the past while I've been discussing the Amateur's Code and its place in our community. I've shown that it was published in 1927, despite credits to the contrary and it's possible that it existed since 1923. I've discussed the original code, how it evolved and what changes have been made across the decades since.
<p>
I'd like to take this opportunity to compare the original from 1927 to a revision that I've constructed using the various versions that have been published since. Originally I was going to use the current 2022 version in the ARRL handbook to discuss this, but it's completely different from the one shown on the ARRL website today, which appears to be more recent, that it made little sense to pick one over the other.
<p>
Back to 1927, or 1923 if you like, written by Paul M. Segal 9EEA, or W9EEA, Director, Rocky Mountain Division and General Counsel of ARRL.
<p>
The Amateur's Code
<p>
I - The Amateur is Gentlemanly. He never knowingly uses the air for his own amusement in such a way as to lessen the pleasure of others. He abides by the pledges given by the A.R.R.L. in his behalf to the public and the Government.
<p>
II - The Amateur is Loyal. He owes his amateur radio to the American Radio Relay League, and he offers it his unswerving loyalty.
<p>
III - The Amateur is Progressive. He keeps his station abreast of science. It is built well and efficiently. His operating practice is clean and regular.
<p>
IV - The Amateur is Friendly. Slow and patient sending when requested, friendly advice and counsel to the beginner, kindly assistance and cooperation for the broadcast listener: these are marks of the amateur spirit.
<p>
V - The Amateur is Balanced. Radio is his hobby. He never allows it to interfere with any of the duties he owes to his home, his job, his school or his community.
<p>
VI - The Amateur is Patriotic. His knowledge and his station are always ready for the service of his country and his community.
<p>
It has a certain "quality" about it. Leaving aside that it's written with a male radio amateur in mind, it represents what the character Dennis Denuto in the 1997 Australian movie "The Castle" refers to as "It's just the vibe of the thing".
<p>
I present to you an updated version of the code in an attempt at preserving that vibe whilst taking into account that we're not in 1923 any longer:
<p>
The Radio Amateur is CONSIDERATE and RESPECTFUL...never knowingly behaving in such a way as to lessen the pleasure of others.
<p>
The Radio Amateur is LOYAL...offering encouragement and participation to the global amateur community.
<p>
The Radio Amateur is PROGRESSIVE...keeping abreast of science, striving to build and operate their station above reproach.
<p>
The Radio Amateur is FRIENDLY...patient; offering friendly advice and counsel to the beginner; kindly assistance, cooperation and consideration for the interests of others. These are the hallmarks of the amateur spirit.
<p>
The Radio Amateur is BALANCED...radio is a hobby, never allowing it to interfere with any of the duties owed to home, work, school or community.
<p>
The Radio Amateur is SUPPORTIVE...knowledge, station and skills always ready for service to country and community.
<p>
Hopefully you've followed along with the evolution of this discussion and find the reasoning for it as compelling as I do. Of course this is just one perspective on what a revised Amateur's Code might look like and I am offering it as a topic of discussion to the entire global amateur radio community. I hope that it provides food for thought, talking points and encouragement to ask questions.
<p>
I will reiterate my thanks to the WorldRadioHistory.com website where you can find many of the earliest editions of the ARRL handbook. If you have any of the missing editions, or better copies than those available, I'd encourage you to share them to continue to preserve the history of our community.
<p>
I'm Onno VK6FLAB
Listen:
The Patriot in Amateur Radio
Foundations of Amateur Radio
<p>
It's been a while since I looked up the word "patriotic". Depending on which dictionary definition you use it could be: "showing love for your country and being proud of it", or it could mean: "having or expressing devotion to and vigorous support of one's country".
<p>
Synonyms for the word patriotic include "nationalist" and "nationalistic" and it relates to words such as "chauvinist", "jingoist" and "fervent". Jingoist means having or showing excessive favouritism towards one's own country.
<p>
That said, the original Amateur's Code published in 1927 says that:
<p>
The Amateur is Patriotic. His knowledge and his station are always ready for the service of his country and his community.
<p>
The 2022 ARRL handbook says:
<p>
The Radio Amateur is PATRIOTIC...station and skill always ready for service to country and community.
<p>
The ARRL website is slightly different:
<p>
The Radio Amateur is PATRIOTIC...His/[Her] station and skills are always ready for service to country and community.
<p>
Based on the meaning and connotations of the word "patriotic", I think that the sixth clause of the Amateur's Code is a political statement. It came at the close of World War One and in that context it makes sense.
<p>
I will also note that the word "patriotic" means different things to different people. For some it's a positive concept, for others it's the opposite and I think as a result it's a problematic concept in the world today.
<p>
If that's not clear to you, consider the notion of patriotic to a person living in the United States of America versus a person living in Ukraine, or a person living in North Korea, Sudan, China or Japan. Each of these countries have different concepts of the idea of patriotic which might not actually be compatible with each other.
<p>
Should we as a global community encourage cohesion or encourage incompatibility?
<p>
A more inclusive word might be "loyal", but we've already covered that. I've offered the following revision of the original loyalty clause to be:
<p>
The Radio Amateur is LOYAL...offering encouragement and participation to the global amateur community.
<p>
We could add the word country to that and dispense with the patriotic clause altogether, but I think that detracts from what the sixth clause is attempting to achieve, the sharing of station and skill to country and community.
<p>
What if we replace the word "patriotic" with "supportive" instead? I also think that the lost word "knowledge" is separate from station and skill and I think it has a place in this clause.
<p>
The clause would read:
<p>
The Radio Amateur is SUPPORTIVE...knowledge, station and skills always ready for service to country and community.
<p>
I'm aware that, given the wide range of meanings for the word "patriotic" across Earth, this is likely to be controversial, but in considering this version, please consider the level of emotion included in your feeling of the word "patriotic" versus the emotion for the word "supportive". It seems to me that reducing the level of emotion in a code of conduct is a positive evolution.
<p>
What are your thoughts on the matter?
<p>
I'm Onno VK6FLAB
Listen:
Finding balance in Amateur Radio
Foundations of Amateur Radio
<p>
When you are absorbed in a hobby like amateur radio it's easy to lose track of the world around you. I freely admit to spending many hours on this hobby and it wasn't until I spent some effort taking stock that I discovered just how much time I spent.
<p>
The fifth clause of the Amateur's Code attempts to formalise this behaviour and I confess that it's taken me several years to find a more reasonable balance. Let's review the original 1927 published version of this clause. It reads:
<p>
The Amateur is Balanced. Radio is his hobby. He never allows it to interfere with any of the duties he owes to his home, his job, his school or his community.
<p>
It's interesting to note that in one of the oldest documents describing our community it refers to our activity as being a hobby. I'm noting this because there have been plenty of treatises written on the notion that amateur radio is a public service and not a hobby.
<p>
This clearly states that in the opinion of the General Counsel of the ARRL in 1927, Amateur Radio is a hobby and frankly, I'm fine with that.
<p>
The 2022 ARRL handbook removes the reference to hobby and words it:
<p>
The Radio Amateur is BALANCED...radio is an avocation, never interfering with duties owed to family, job, school or community.
<p>
The ARRL website reintroduces the concept of a hobby like this:
<p>
The Radio Amateur is BALANCED...Radio is a hobby, never interfering with duties owed to family, job, school or community.
<p>
I'll note that the definition of avocation is "a hobby or minor occupation" and I'm not sure what the clause gains by using a word that I had to look up in the dictionary. Consider for a moment if your first language isn't English, why use "avocation" when "hobby" is the same thing?
<p>
The original used the phrase: "never allows it to interfere with any of the duties he owes", this puts amateur radio as a hobby at the bottom of the pecking order in the list of things you do. The 2022 version waters this down to "never interfering with duties owed", essentially elevating the hobby above some of those other duties. I don't think that this is an improvement.
<p>
I'm a fan of amateur radio, but I think that in the scheme of things it needs to take the place of a hobby, not an activity that has the ability to be prioritised over any of your other duties. If it does, where is the line? What is more important and what isn't? Should this be something that we in our code of conduct endorse? What's next, telling amateurs specifically what they should be doing? I think not.
<p>
One thing that's worth exploring is the concept of "job". A job is your occupation, tow truck driver, radio astronomer, submariner or accountant. The original meaning, going back to the 1550's is "an activity that an individual performs in exchange for a specific fee or payment".
<p>
What if you don't have a job? What if you're retired, unemployed or have some other lifestyle?
<p>
What if we replace the word "job" with "work", defined as "a physical or mental activity that is performed in order to accomplish or produce something"?
<p>
This could make the fifth clause look like this:
<p>
The Radio Amateur is BALANCED...radio is a hobby, never allowing it to interfere with any of the duties owed to home, work, school or community.
<p>
It's short and sweet, uses simple language and it covers everything that the original document was attempting to achieve, and as a bonus it no longer requires you to have a job.
<p>
I'm Onno VK6FLAB
Listen:
Being friendly in Amateur Radio
Foundations of Amateur Radio
<p>
The fourth clause of the original Amateur's Code, published in 1927 has a lot to say about the tone of amateur radio. It says:
<p>
The Amateur is Friendly. Slow and patient sending when requested, friendly advice and counsel to the beginner, kindly assistance and cooperation for the broadcast listener: these are marks of the amateur spirit.
<p>
The 2022 ARRL handbook tweaks that into:
<p>
The Radio Amateur is FRIENDLY...slow and patient operating when requested; friendly advice and counsel to the beginner; kindly assistance, cooperation and consideration for the interests of others. These are the hallmarks of the amateur spirit.
<p>
The ARRL website adds a pronoun and updates some of the language:
<p>
The Radio Amateur is FRIENDLY...He/[She] operates slowly and patiently when requested; offers friendly advice and counsel to beginners; kind assistance, cooperation and consideration for the interests of others. These are the marks of the amateur spirit.
<p>
I'm not quite sure what the idea behind this change is. The original referred to "slow and patient sending" in an era when that meant slowing down your Morse Code. I'm not sure what "operating slowly" means, unless it's asking the amateur to speak slowly or to operate their fixed speed FT8 station slowly, hardly the same thing as reducing the speed of your Morse key.
<p>
There's also a reference to the "broadcast listener", something which we refer to as shortwave listeners today. Essentially, be kind to the people around you and accommodate their limitations when you are asked, which is what the rest of the words have been morphed into.
<p>
I think that being friendly and patient is a worthy aim and I don't think that it should be requested. The original used the word friendly twice, added kindly and used counsel, advice, assistance and cooperation.
<p>
All this is collaborative language, encouraging the amateur to participate and being friendly and considerate when they do.
<p>
I also note the difference between a "mark" and a "hallmark". The word hallmark means a mark stamped on articles of gold, silver, or platinum by the British assay offices, certifying their standard of purity.
<p>
I think that certifying friendliness to a standard of purity is a worthy objective and I think that using the word "hallmark" instead of "mark" elevates the clause to a standard worth achieving. I think that the 2022 ARRL handbook use of the word "hallmark" is an example of an improvement of the code that should be embraced.
<p>
With that in mind, removing the superfluous pronouns, given that "The Radio Amateur" encompasses anyone with a license, here's an alternative for the fourth clause of the Amateur's Code.
<p>
The Radio Amateur is FRIENDLY...patient; offering friendly advice and counsel to the beginner; kindly assistance, cooperation and consideration for the interests of others. These are the hallmarks of the amateur spirit.
<p>
It's a little longer than I'd like, but I think it leaves less room for ambiguity in the notion of operating slowly and it no longer requires that someone needs to ask for an amateur to be patient. I think that overall, it encourages good behaviour in a world where we can bash out an angry reply at the whim of the nearest keyboard.
<p>
What do you like about this version and what would you change?
<p>
I'm Onno VK6FLAB
Listen:
Progressiveness in Amateur Radio
Foundations of Amateur Radio
<p>
The third clause of the original Amateur's Code reads:
<p>
The Amateur is Progressive. He keeps his station abreast of science. It is built well and efficiently. His operating practice is clean and regular.
<p>
The 2022 ARRL handbook is similar:
<p>
The Radio Amateur is PROGRESSIVE...with knowledge abreast of science, a well-built and efficient station and operation above reproach.
<p>
The ARRL website adds in some pronouns and removes the science from the clause:
<p>
The Radio Amateur is PROGRESSIVE...He/[She] keeps his/[her] station up to date. It is well-built and efficient. His/[Her] operating practice is above reproach.
<p>
I'm not sure what prompted this alteration and frankly, I'm not a fan. Pronouns aside, science is at the heart of what it is that we do and that has been the case since the very first amateur went on air. It's also bewildering to me that knowledge and science has been transformed into keeping your station up to date, which means something else entirely.
<p>
The original is about learning and education, in my opinion the ARRL website version is about shopping and frankly it's distasteful in a world where we as amateurs are renowned for experimentation and constructing a solution from parts.
<p>
It raises another question.
<p>
Who actually made this change and what process exists to actually implement it? Is it the whim of an individual, or is there a committee that was elected to investigate and update the code? If it was an elected body, how does it represent me in Australia and how does it represent any amateur beyond the shores of the United States, or even beyond the membership of the ARRL?
<p>
Consider the scope of amateur radio as a global activity. The Amateur's Code has spread far and wide in the past century, well beyond its apparent origins as a page in the third edition of the ARRL handbook in 1927.
<p>
In my opinion this code is not an ARRL owned document, it belongs to all amateurs across Earth and it should be treated as such. As I've said before, it's a living document and it has evolved over time, but that doesn't mean it can be changed on a whim. There should be rigorous discussion in a public forum that informs any such change and at present I see no evidence of that at all.
<p>
To illustrate its reach further, the IARU has a document called "Ethics and Operating Procedures for the Radio Amateur", with Edition 3 published in 2010. It contains a copy of the code with yet another version of clause three:
<p>
The Radio Amateur is PROGRESSIVE... He keeps his station up to date. It is well-built and efficient. His operating practice is above reproach.
<p>
Clearly change is being implemented somewhere and it might well be that this version informed the current version on the ARRL website, 12 years later. I'll also note that there is a copyright statement in that IARU document that contains a whole lot of, in my opinion, unenforceable verbiage, including the requirement that any copy or portion is required to include a copyright notice, which in the case of the included Amateur's Code is murky at best. I also note that it credits Paul Segal in 1928, something which we've already established is wrong, given that the code appears in print in 1927 and has been credited to him as far back as 1923.
<p>
Back to the clause, I think that keeping science as an integral part of the conversation is essential. I'm going to repeat the original clause as published for reference.
<p>
The Amateur is Progressive. He keeps his station abreast of science. It is built well and efficiently. His operating practice is clean and regular.
<p>
In addition to science, there's a statement about how to build and how to operate. It's a little curious to use the word progressive, but it means to happen or develop gradually or in stages. In other words, you don't need to be perfect on day one, but you do need to strive for the objectives as part of an evolutionary process.
<p>
So, progressive, science, well built and well operated. That seems like a recipe for lifelong learning, in my opinion a lofty goal to strive for.
<p>
What if we lost the last century pronouns, removed the shopping imperative and kept the tone:
<p>
The Radio Amateur is PROGRESSIVE...keeping abreast of science, striving to build and operate their station above reproach.
<p>
Would such a clause inspire you to do better, to build and grow as an amateur, to improve and learn?
<p>
I'm Onno VK6FLAB
Listen:
Loyalty in Amateur Radio
Foundations of Amateur Radio
<p>
The second clause of the original Amateur's Code reads:
<p>
The Amateur is Loyal. He owes his amateur radio to the American Radio Relay League, and he offers it his unswerving loyalty.
<p>
The 2022 ARRL handbook presents it with the following words:
<p>
The Radio Amateur is LOYAL...offers loyalty, encouragement and support to other amateurs, local clubs and the American Radio Relay League, through which Amateur Radio in the United States is represented nationally and internationally.
<p>
The ARRL website goes the extra mile to make this hard work and states that:
<p>
The Radio Amateur is LOYAL...He/[She] offers loyalty, encouragement and support to other amateurs, local clubs, the IARU Radio Society in his/[her] country, through which Amateur Radio in his/[her] country is represented nationally and internationally.
<p>
Pronouns aside, this has got to be one of the more tortured efforts you might subject an entire group of humans to. Written in an attempt to enumerate each and every specific version of the global amateur radio community, it excludes more than it includes and in doing so completely fails the one thing it aims to achieve, a sense of belonging, being part of something bigger than you.
<p>
So what does loyalty look like?
<p>
Is providing constructive feedback loyalty? Is giving your time and energy a loyal thing? What about being a member of a club?
<p>
The dictionary suggests that loyalty is a strong feeling of support or allegiance. Originally the code suggested that this should be directed at the ARRL, even the handbook continues to suggest that today, but is that relevant for me here in Australia? Should I be a loyal member of the ARRL, or should I be a loyal member of the WIA? What if there is a second body in your country? In Australia there is another organisation attempting to reshape the hobby, RASA, the Radio Amateur Society of Australia, should I be loyal to that? Can I be loyal to both, or neither? What happens if I am not comfortable with either organisation, who should I be loyal to?
<p>
National bodies aside, what about clubs? Am I required to be a club member and be loyal to it? What if I'm a member of more than one club? Should I be more loyal to one than the other? Should I be more loyal to the national body or my local club? What if I'm not a member of any club? What should I be loyal to then?
<p>
What if loyalty is coupled to an idea instead of a specific body? What might that idea look like? The revised version of the clause already includes concepts such as encouragement and support to other amateurs. What if we just omit any specific bodies and replace it with the idea of the global amateur community in all its many splendored diversity?
<p>
While we're looking at this, the word encouragement includes the action of giving someone support, confidence or hope, so we're repeating ourselves by using support and there's plenty of other things we could share around.
<p>
Here's a philosophical question to wrap your mind around. If you have a drivers' license, but you don't drive, are you a driver? Similarly, if you have an amateur license, but you don't do anything with it, are you an amateur? Perhaps the nub of this lies in participation.
<p>
Taking those thoughts into account, we could rephrase the second clause of the Amateur's Code to:
<p>
The Radio Amateur is LOYAL...offering encouragement and participation to the global amateur community.
<p>
If this clause was part of the Amateur's Code, would it help you feel like you belonged, would it travel beyond the borders of your country and would you feel part of something bigger?
<p>
I'm Onno VK6FLAB
Listen:
Consideration in Amateur Radio
Foundations of Amateur Radio
<p>
The first clause of the original Amateur's Code reads:
<p>
The Amateur is Gentlemanly. He never knowingly uses the air for his own amusement in such a way as to lessen the pleasure of others. He abides by the pledges given by the A.R.R.L. in his behalf to the public and the Government.
<p>
The 2022 ARRL handbook version states it like this:
<p>
The Radio Amateur is CONSIDERATE...never knowingly operates in such a way as to lessen the pleasure of others.
<p>
Today the ARRL website presents it as:
<p>
The Radio Amateur is CONSIDERATE...He/[She] never knowingly operates in such a way as to lessen the pleasure of others.
<p>
It's surprising to see the addition of the He/[She] pronoun when nothing is added by doing so, in fact for some amateurs this actually reduces its relevance, something which I've spoken about before.
<p>
We could just simply change the words to remove the pronoun entirely, but does that actually cover all of what we want it to mean? Should this consideration be limited to operating, or should we go beyond that? What about conduct in a club setting, or on social media, email or SMS?
<p>
Some of these activities are conducted as a radio amateur and some are not. If we're limiting ourselves to amateur radio, not an unreasonable place to start given that we're talking about a document called "The Amateur's Code", we should really discuss the nature of amateur radio today.
<p>
I find myself in a community of amateurs, not a radio in sight, exchanging thoughts, opinions and experience that go beyond the concept of operating. I will note that there are legal definitions in our hobby that describe the notion of operating that do not include QRZ.com, email or Reddit and there is an argument to be made that operating falls strictly within the bounds of a licensed amateur activity.
<p>
That said, since "no man is an island", first uttered in 1624 by John Donne, neatly illustrates that although we're licensed amateurs, we do more than key our radios alone and even when we do, there are activities that affect others who are not operating as such.
<p>
When we discuss things with each other, face to face, that's not a licensed activity, even if both of us are amateurs. Neither is sending an email to another amateur, or commenting on a social media post. Standing in a club and teaching is also not a licensed amateur activity and cannot be considered under the idea of "operating".
<p>
All of what this clause is attempting to say is to be considerate. Don't reduce the pleasure of others by doing things that are unacceptable. It goes to how you are expected to be, to conduct yourself, to behave.
<p>
To incorporate this idea that what you do with other amateurs goes beyond operating, I think the word "operate" needs to be changed to the word "behave".
<p>
I'd also like to explore the word "gentlemanly" from the original text. Synonyms for this include civilised, courteous, honourable and polite to name a few. It seems to me that words like that would benefit our interactions within our community, not to mention beyond it.
<p>
One word that comes to mind is "respectful", something that lies at the heart of how we conduct ourselves towards each other.
<p>
So, if we drop the pronouns, update the word operates and add in respect, a revised clause one could be:
<p>
The Radio Amateur is CONSIDERATE and RESPECTFUL...never knowingly behaving in such a way as to lessen the pleasure of others.
<p>
Let me hasten to point out that I'm proposing this as a starting point for discussion. This is an activity that should go beyond one individual, it should also go beyond a single organisation. Amateur Radio is a global activity and it would do well for us to consider all of humanity when drafting a code of conduct which is essentially what the Amateur's Code is attempting to achieve.
<p>
So, how would you approach the first clause, what do you like, what do you think is missing, what would it need for you to consider it words to live by?
<p>
I'm Onno VK6FLAB
Listen:
A code for amateurs
Foundations of Amateur Radio
<p>
The American Radio Relay League or ARRL is one of the oldest amateur associations on Earth. 1926 saw the birth of "the Radio Amateur's Handbook", the first edition of what we now know as "The ARRL Handbook For Radio Communications" featured chapters on what it means to be an amateur, how to build and operate a station, how propagation works and how to experiment. The very first handbook had 5000 copies printed and thanks to the website WorldRadioHistory.com we have access to a signed copy by the author himself, the Communications Manager of the ARRL, Francis Edward Handy (W1BDI). He starts the 228 page book with the following words:
<p>
This Handbook is written as a guide for member-operators of the League. It is also useful as a source of information to the man who wants to take part in amateur radio activity but who has no idea of how to get started. Written first of all for the beginner, such an amount of useful and up-to-date information has been added that the Handbook in its present form is equally valuable as a compendium of information for the experienced brass-pounder and the beginner alike.
<p>
The first edition doesn't show a cover price, but the third edition, published a year later shows a charge of $1. The 2022, or 99th edition has nearly six times as many pages, 1280 of them, it costs ten times as much per page and sells for nearly 50 times as much at $49.95. The current handbook features topics such as Radio electronics theory and principles, Circuit design and equipment as well as articles and projects that include 3D printing, portable battery selection, safe antenna and tower work practices and comes in a variety of formats including electronic and box sets.
<p>
I'm giving this background to give you a sense of how things have evolved in the past century. For example, one thing that the very first edition didn't have was a page called the Amateur's Code. The oldest copy I've found appears in the 1927 or third edition.
<p>
If you're familiar with the words, you're in for a treat. If not, sit back and imagine it's 1927, or 1923, more on that in a moment.
<p>
The Amateur's Code
<p>
I - The Amateur is Gentlemanly. He never knowingly uses the air for his own amusement in such a way as to lessen the pleasure of others. He abides by the pledges given by the A.R.R.L. in his behalf to the public and the Government.
<p>
II - The Amateur is Loyal. He owes his amateur radio to the American Radio Relay League, and he offers it his unswerving loyalty.
<p>
III - The Amateur is Progressive. He keeps his station abreast of science. It is built well and efficiently. His operating practice is clean and regular.
<p>
IV - The Amateur is Friendly. Slow and patient sending when requested, friendly advice and counsel to the beginner, kindly assistance and cooperation for the broadcast listener: these are marks of the amateur spirit.
<p>
V - The Amateur is Balanced. Radio is his hobby. He never allows it to interfere with any of the duties he owes to his home, his job, his school or his community.
<p>
VI - The Amateur is Patriotic. His knowledge and his station are always ready for the service of his country and his community.
<p>
This version is credited to Paul M. Segal 9EEA, Director, Rocky Mountain Division ARRL.
<p>
The code appears on page 9 of the 1927 edition of the handbook. It uses Roman numerals to identify each point, the title is beautifully rendered with the Old English Typeface and it's shown inside a rectangle on a page on its own.
<p>
Over the next 45 years the text stays the same. There are changes like colons to semi-colons, an additional comma and the evolution from Roman numerals to modern numbers, and then written numbers and finally the removal of the numbers entirely. At one point the title is changed from "Amateur's Code" to "Our Code", but that only lasts for one edition. Speaking of editions, the 1936 edition, the thirteenth in the series, is referred throughout as the 1936 edition, superstition is alive and well.
<p>
The credit changes over time as well. In 1929 Paul's callsign is changed from 9EEA to W9EEA.
<p>
In 1943 we see a once-off credit appear. It states that the code was written in 1923 by Lieut.-Commander Paul. M. Segal, General Counsel of ARRL. It's the only credit that shows a different year from any of the other references which all point at 1928 as the original year, which is what the ARRL uses today. Interestingly, we have a copy of the handbook from 1927 that features the code, so it's entirely possible that 1923 is actually correct and it's not hard to imagine that a poorly printed 3 looks like the remains of the number 8.
<p>
To add to this, there's a 1944 FCC report to the President of the United States of America that contains a reference to "Lieutenant Commander Paul. M. Segal, the radio industry attorney". In addition there's an announcement in the New York Times, dated 25 May 1968 with the headline: "Paul M. Segal Is Dead at 68; Expert in Communications Law"
<p>
I don't have access to any version of the Second Edition of the handbook which had two print runs in 1927. It's entirely possible that the code appeared there, but I have no evidence either way. I do believe that Paul M. Segal, 9EEA Director of the Rocky Mountain Division of the ARRL is the same person as Lieutenant Commander Paul. M. Segal, General Counsel of ARRL and radio industry attorney who became a silent key in 1968.
<p>
Credits, layout and font changes aside, 1973 sees the first time when the words of the Amateur's Code actually change.
<p>
Let me illustrate.
<p>
The original first clause reads:
<p>
I - The Amateur is Gentlemanly. He never knowingly uses the air for his own amusement in such a way as to lessen the pleasure of others. He abides by the pledges given by the A.R.R.L. in his behalf to the public and the Government.
<p>
In 1973 that's changed to:
<p>
One
The Amateur is considerate . . .He never knowingly uses the air in such a way as to lessen the pleasure of others.
<p>
The first four clauses are modified to greater and lesser degree, clause five and six stay the same.
<p>
Today the ARRL website shows the first clause as:
<p>
The Radio Amateur is CONSIDERATE...He/[She] never knowingly operates in such a way as to lessen the pleasure of others.
<p>
And the credit reads: "adapted from the original Amateur's Code, written by Paul M. Segal, W9EEA, in 1928"
<p>
It's noteworthy that going back to the original text the very first clause encourages the amateur to be gentlemanly, something which we can relate to in terms of being respectful, polite and civil.
<p>
It's also clear that the Amateur's Code is a living document and has been moving with the times. I think that we as a community have the opportunity to participate in another review and I will investigate and share with you some of my thoughts on the matter.
<p>
I think that it is important that we have a code of conduct that reflects our values and at present the best starting point we have is the Amateur's Code.
<p>
I'm Onno VK6FLAB
Listen:
The microphone gain game ...
Foundations of Amateur Radio
<p>
One of the most misunderstood settings on your radio is the microphone gain. You'll often hear people talking about adjusting it up or down depending on what they hear and the results are often displeasing to the ear.
<p>
The very first thing to know is that the microphone gain is likely the single most audible setting on your radio, right after the tuning frequency. It's pretty much the first variable between your voice and your transmitter. Set it too low and you'll hear nothing, set it too high and you'll hear gibberish.
<p>
I said it's pretty much the first thing, but it's not the very first. That's your voice, unique in all its glory, loud, soft, happy, sad, funny or not, it's the thing that your microphone captures to transmit. Closely coupled to your voice is the distance between your mouth and your mike. The closer you are, the louder, the further, the softer and the more background noise creeps in.
<p>
As an aside, speaking of noise, there's background noise at play, but there's also the noise that comes from the audio circuitry itself, which can for example change depending on the temperature of your radio. I'm going to refer to both as noise here, even though they're slightly different.
<p>
So, starting with the ideal model where you always speak in the same way, at the same volume, at the same distance from the microphone, with a constant temperature in your radio, at all times, the next thing is the microphone gain, or gain.
<p>
Gain is an imperfect attempt at corralling your utterings into electrical signals without causing the audio circuit to distort or drown in noise. Distortion comes as a result of overloading of the audio circuit when the gain is too high, causing clipping, which essentially changes the audio waveform into something that no longer resembles your voice. At the low end of the gain range there is no difference between audio and noise which results in your voice being buried inside a hissing noise.
<p>
You might wonder why we don't just build transmitters that cannot clip and increase your volume. Well, we do. We use things like AGC, or Automatic Gain Control to attempt to prevent such things from happening, but this isn't perfect.
<p>
All this results in the microphone gain being a setting that you need to tune to your voice and adjust as things change. Overall, the best outcome is when you set the gain so the AGC just engages when you talk normally.
<p>
This gain setting also applies to computer generated signals, often fed into your radio via an audio or microphone input. If you set the gain too low, noise is the problem, set it too high and the Automatic Gain Control will distort the signal to the point where it no longer works and causes interference for everyone else including the station that you're trying to contact.
<p>
On older radios the output power was fixed. This is also true for Software Defined Radios. To reduce output power, you can change the microphone gain down and reduce the power. Change it to halfway and your output power is essentially reduced to half power. This works for a range of settings, but get too low and we're back to noise and audio fighting each other.
<p>
The opposite isn't true.
<p>
You cannot increase the microphone gain to increase power. The moment you exceed the audio circuit range your signal is distorted. On an SDR this means that you're exceeding the ability of the Analogue to Digital converter to represent your audio. In digital terms, zero means no sound and all on means 100%. If your audio is so loud as to only be 100% on, that's like sending a tone out the transmitter, resembling anything but your voice.
<p>
All of what I've talked about is related to SSB signals and to some extent AM. FM is a different animal entirely. For starters, output power on FM is fixed. The next difference is the signal or channel width. Without going into full detail, FM comes in different widths, WFM or Wideband FM, NFM, or Narrowband FM, and between the two, "normal" FM. To make things more fun, not everyone agrees on what each one means at any given time. Also, channel width and channel spacing are not the same thing, but that's for another day.
<p>
Gain aside for a moment, consider two matched FM radios using the same channel width. Your voice volume is determined by how much of the channel you use. Louder means wider, softer means narrower. Adjust the gain up, the signal gets wider, but the limit of the channel width remains, get too high and it clips at the channel width and distorts. At the other end, changing the gain down, you'll use less of the channel width and eventually the noise and your voice will be at the same level and you won't be heard.
<p>
Let's look at what happens when you use a normal FM signal to transmit to a narrowband FM receiver. Essentially your signal is too wide and the result is that your voice will be clipped unless you speak really softly or if you've set the gain really low, either way comes with more noise.
<p>
Similarly, if you transmit a narrowband FM signal to a normal FM receiver, then your voice will be very low, regardless of the microphone gain setting and turning it up will only distort it due to clipping inside your transmitter.
<p>
So, for FM, before fiddling with the gain, make sure that you're using the same FM mode as the other station. One thing to remember is when you use a repeater, if the audio is always too loud for everyone, your mode is probably too narrow. Similarly, if the audio is always too soft and you always need to turn up the volume on your radio, your mode is likely too wide. Check your radio specifications to determine what each mode means.
<p>
In broadcast audio this whole thing is managed by calibration using standard tones, but as amateurs we tend to rely on other people reporting their feelings on the quality of your voice with the often heard admonishment to adjust the microphone gain.
<p>
I'm Onno VK6FLAB
Listen:
What's with the repeater offset again?
Foundations of Amateur Radio
<p>
As a new amateur one of the initial perplexing issues you're confronted with is setting up your first radio to talk to the local repeater. The question is so common that it's almost an invisible rite of passage to a new licensee. While I'm a fan of learning, there is plenty of that to go round and setting up your radio to talk to a repeater shouldn't be a hurdle to getting on air and making noise.
<p>
Ignoring the whole repeater thing for a moment, let's consider your radio. It doesn't matter if it's a handheld, a base station, a boat anchor or something else. To participate in the whole repeater experience, you need to tune your radio to hear it.
<p>
Technically, if I told you that you could tune to a local repeater on 146.750 MHz, that would be enough information to get you going, but this depends entirely on a set of standard assumptions that are likely not obvious to you. Let's explore what's going on.
<p>
Given that frequency, you can set your radio to 146.750 MHz and in most cases, you'll be able to hear the repeater. To actually participate, you would need to do some more work to get your transmitter to be heard.
<p>
As I said, standards are what makes that possible, but like every human endeavour, caution must be applied. As Andrew Tanenbaum said: "The nice thing about standards is that you have so many to choose from." With that in mind, let's proceed. Before you start yelling, I'll add caveats at the end.
<p>
Armed with a repeater frequency, you have enough information to get on air, but it assumes that you know a couple of things. So let's delve into those assumptions.
<p>
For starters, there is an assumption that you're aware that to operate a repeater you must transmit on a different frequency than what you're listening on. Why that is the case is a whole other discussion which I'll leave for today.
<p>
There is the assumption that you know that the two frequencies, one for listening, one for transmitting, are separated from each other by a known distance, a so-called offset.
<p>
You're also assumed to know that this offset is fixed but different for each band.
<p>
There's more, but let's start here.
<p>
For your radio to transmit on a different frequency than you listen, you must tell it to. In many cases tuning your radio to a so-called repeater frequency will already do this for you, but not always.
<p>
You might need to specifically program your radio for repeater operation, or turn on the offset mode, or use two memories, or some other thing specific to your radio. Read The Friendly Manual, I know you know how.
<p>
The next step is to look at the band you're on. In this case the 2m band. This means that the standard says that the difference between the receive and transmit frequency is 600 kHz. I'm studiously ignoring other bands at this moment because, standards.
<p>
At this point you know that your radio should be tuned to 146.750 MHz, it should be in repeater mode and the offset should be 600 kHz. That's when the next question arises, should that be plus 600 or minus 600?
<p>
Guess what, another standard. If the receive frequency is less than 147 MHz, the answer is minus 600 kHz. If it's more than 147 MHz, it's plus 600 kHz.
<p>
Notice that I didn't specify what happens if it's exactly 147 MHz? That's because nobody knows. Seriously though, the local repeater owner will know, but you can try either and get your answer.
<p>
Now for the caveats.
<p>
Let's start with the 147 MHz cross-over exception. This isn't global, for example repeaters in California use several different ranges for such a cross-over point.
<p>
I also didn't tell you about repeaters on other bands because the offset depends on where you are. In many cases the 70cm repeater offset is 5 MHz, but in Europe it's mostly 7.6 MHz, unless it's 9 MHz. The 10m repeater offsets are often 100 kHz, but sometimes they're 1 MHz, similarly the 6m repeater offset is 1 MHz, except when it's not.
<p>
The point being that starting with a receive frequency, there's a great number of assumptions, many of which you'll need to discover for your own location. A great resource which I've mentioned before is the brainchild of Garrett KD6KPC, the repeaterbook.com website and app, maintained by a global group of volunteers, which lists many repeaters and their specific settings, frequencies and locations.
<p>
So, armed with this knowledge, I expect that you can now find a local repeater and make use of it. When in doubt, contact the owner and ask for help, they're a friendly bunch. Remember to say thank you!
<p>
So, what excuse do you have not to get on air and make noise?
<p>
Oh, before I forget, if you don't hear anything, or if transmit isn't doing what you expect, check that you've configured CTCSS, another assumption.
<p>
I'm Onno VK6FLAB
Listen:
Take a long hard look at our community ...
Foundations of Amateur Radio
<p>
The art of amateur radio is a globe spanning activity, held together by radio waves and the promise of a community with a shared uncommon interest. The strength of a community depends entirely on the members of that community. Without the efforts of each individual amateur, our worldwide license to experiment is doomed.
<p>
You might ask yourself what part you have to play in this?
<p>
Consider what would happen if a group of amateurs decided to transmit on an unlicensed frequency, or purposefully interfered with other legal users. It's obvious that the regulatory response to such illegal activities would be swift and left unchecked, it would spark the end of our hobby.
<p>
What prevents that from happening is our common purpose, our common interests, our willingness to address such behaviour, or said in another way, our community standards. It's the thing that keeps us talking, sharing, learning, experimenting and having fun along the way.
<p>
I've been told many times that I shouldn't expect all amateurs to be friends, but consider for a moment the sheer diversity of our community. For starters we're scattered around the planet. We have different cultural and political sensibilities, we have different religions and expectations. We don't even speak the same language, even if you forget that the Japanese station you just had a QSO with was using phonetics not even close to their native language.
<p>
Those differences are mostly attributes of geography, but they don't end there. We have differences in our households and family structures, our work life and finances, our play time and our interests. We also differ in age, skin colour, gender and even our sexuality, orientation and gender identity.
<p>
Even among all those differences, we are still radio amateurs together with our personal preferences for Icom, Yaesu, Kenwood or some other brand, our desire to use QRP or kilowatts, our need to use a Morse key, our voice, or a computer. We choose to use a repeater, or not, choose HF or not, like to chat, or not, build antennas, or not.
<p>
So it's with all those differences in mind that I'm distressed to report that yet another amateur has been bullied out of our community. An amateur who joyfully participated in this community, who made videos, wrote software, learnt and shared. Like others I know, she was bullied in our community because she was different and it's not the first time I've witnessed this behaviour and it's not the first time I've called out this unacceptable conduct by so-called members of our community. Different, how you ask? Does it really matter, or are you asking to determine if there was a valid reason for making her feel uncomfortable?
<p>
To be clear, our community is a welcoming environment, filled with hope and joy, but there is a small rotten element in our midst that we need to rip out root and branch, much like we would if it was deliberate HF interference.
<p>
You might think that given that this abuse exists on reddit, YouTube, Twitter, Facebook, QRZ, email, telephone, letterbox, in clubs and on-air, that it's a majority experience. That's not the case. The same individuals harass fellow amateurs across multiple platforms as entertainment causing untold harm to their victims.
<p>
The Standard You Walk Past Is The Standard You Accept. It's not just up to victims of bullying and harassment in a community to speak out. As members of our community, we amateurs have a responsibility to speak out also. Anyone who doesn't is part of the problem. Our community is so diverse as to never be one single thing. A bully is a bully, no matter which words are used to sugar coat it.
<p>
I'd like to invite you to consider any bullying you accepted in silence, either personally, as a witness, directly, or indirectly. This community is strong, it's resilient, it's resourceful, it's you and I and it's our duty to stand tall and speak out, loud and proud, about any victimisation.
<p>
Even if you've never considered that this is happening in your community, look around and notice people leaving the hobby unexpectedly and examine why that might be the case.
<p>
You might ask what it is that you can do to help. For starters, calling it out at every occurrence is part of communicating to the victim that they're not alone. It tells the community that they are part of the solution. It tells the bully that what they're doing is unacceptable.
<p>
I host a weekly net where we talk about amateur radio and discuss issues like this as and when they occur. We've done so in the past and will continue to offer a safe space for members of this community.
<p>
I have and continue to offer my email address, cq@vk6flab.com, for anyone who is struggling with this to discuss any bullying that they are dealing with.
<p>
I have experienced some of what this amateur has gone through at the hands of this community and I will not stand for it any longer and neither should you. Keeping quiet and changing frequency is not the solution as time after time experience has proven.
<p>
Calling out a bully and any bullying behaviour is calling out a vicious minuscule minority with a peanut brain who needs to be read the riot act. They are not welcome in this community. They are few and far between and we really don't need or want them in our midst.
<p>
In my opinion, the community must take ownership of this problem and address it directly, rather than sit on the fence and leave a victim wondering why they're on their own. If you are a victim of bullying in this community, I stand with you and if you are a bully, I'll do everything I can to call you out.
<p>
I'm Onno VK6FLAB
Listen:
Much Ado About ...
Foundations of Amateur Radio
<p>
There are days that my brain just cannot keep up with all the ideas that I have spinning around and today is one such experience. Before I take you on this wild ride I will mention that I'm only going to focus on the amateur radio specific things going on, but I tend to have a couple of projects on the go at any one time, much like a messy desk piled high with paper, books, gadgets, parts and coffee cups, my mind has this sometimes exhausting tendency to see connections between various projects and often this results in deeper rabbit holes, so with that in mind, I'd like to make an attempt at describing all the amateur things that are going on at this very moment.
<p>
So, here goes, hang on!
<p>
It all started with two friends, independently and until now, unbeknownst to each other, playing with a mode called Digital Radio Mondiale, or DRM. It's something I've talked about before. One friend is trying to decode it, the other is trying to generate it. I'm sitting on the side cheering on because I think that there will come a time when I understand enough of my PlutoSDR that I can create any form of any mode and not be limited to the SSB bandwidth that current technologies use and be able to receive and generate say a 20 kHz DRM signal.
<p>
In order to advance my learning, I started the day wanting to describe a PlutoSDR project. I wanted to spend some enjoyable time playing, making some progress and then telling you about it. I did play, I did have fun, I did make progress, but trying to explain precisely what and how was where I came unstuck.
<p>
I began describing the difference between analogue and digital radios and how there's a fundamental difference in how a signal comes to exist in both. That quickly turned into a conversation about I/Q signals, a discussion that I've been putting off for a while because I'm still not happy with my own understanding of it, let alone any attempt to explain it to you in a coherent and hopefully fun way.
<p>
The complexity of explanation was brought home to me during the week when NASA Administrator Bill Nelson used an example to explain an image taken by the James Webb Space Telescope.
<p>
The phrase he used was this:
<p>
"if you held a grain of sand on the tip of your finger at arm's length, that is the part of the universe that you're seeing"
<p>
That seemed pretty clear to me. I could imagine a grain of sand on my fingertip, extending my arm and grasping the idea that hidden behind it was a small slice of the sky representing how big the image was. For me that explanation was excellent, especially when Bill Nelson went on to say that the things you were seeing were galaxies, each made of a hundred billion stars, each likely with planets in orbit.
<p>
Only I discovered that the explanation using a grain of sand wasn't universal. I was surprised to learn that for some it got muddled up with the grains of sand in the universe and the relationship between those and the one on your finger.
<p>
To be clear, I'm not saying that there is anything wrong with misunderstanding, but it reminded me in a visceral way that how we explain things matters and there are plenty of times when my own efforts fail to achieve their intended purpose, of making things easier to understand.
<p>
Given the importance of I/Q signals within the whole conversation on software defined radios, I don't want to do a half baked attempt and fail. I will say this, an I/Q signal is a way of precisely representing a radio signal, but only to stop you thinking about it further.
<p>
I was talking about how my mind accumulates things.
<p>
The NanoVNA that's sitting on my desk, gifted to me by a friend, is a fantastic example of the similarity between it, software defined radio and say a TinySA which I came across last week. Let me unpack that a little.
<p>
A NanoVNA is a piece of testing equipment, as is a TinySA. They test different things. Both have the ability to generate and measure a signal and in that they share the abilities of an amateur radio transceiver that can also generate and receive a signal.
<p>
That right there is a very deep rabbit hole, so I'm going to purposefully step away and continue the journey of observation, only pausing to mention that my PlutoSDR has all the same capabilities and in that it's not alone.
<p>
The fundamental difference between these three devices is software. There are a few other things, but on the whole, software.
<p>
So, I'm carrying around this mush of things that are almost the same, but different, almost understood, but not quite, almost ready to explain, but not yet.
<p>
In an attempt at going forwards by moving sideways, I went on to investigate other things, prompted by people who send me emails. For example, code plugs and DMR and frankly I felt unclean reading the various explanations. I'm a firm believer in Open Source and this is like asking an Icom owner to explain the benefits of using Yaesu hardware.
<p>
Another question was around bending antennas, as-in, what happens when you drive down the road and your VHF antenna bends, or what happens if your HF dipole is bent to fit in your garden. Superficially I can say that the antenna changes as its bounding box changes shape. That means that the feed point impedance will change, as will the resonant frequency. The radiation pattern will also be affected, but sitting down and discovering just by how much is going to take more time than I have available whilst attempting to string together some coherent words on a topic I love.
<p>
So, in an attempt at telling you what's going on in my world of amateur radio, I leave you with this question:
<p>
"What was I talking about again?"
<p>
Now I remember, this is about just how complex, fluid and interesting amateur radio is for me and in that observation lies why I'm here doing what I do.
<p>
"What makes you keep coming back for more?"
<p>
I'm Onno VK6FLAB
Listen:
The power supply connector dance contest...
Foundations of Amateur Radio
<p>
In over a decade of writing a weekly article about all manner of different aspects of our hobby and community, I've never once talked about power connectors for your radio. It's so universal as to be invisible and rarely discussed. So much so, that something you do out of habit, makes another stop dead in their tracks and ask themselves why they never thought of it.
<p>
Despite how you might feel at the time, there's no such thing as a stupid question. The other day a fellow amateur Dave VK6KV asked about a power connector he'd seen at the local electronics store. That question started a group discussion about powering radios and how best to achieve that.
<p>
The very first thing to discuss is that the vast majority of amateur radio transceivers expect a nominal voltage of 13.8 Volt DC. That might sound like a strange requirement, but it's the voltage that comes from a fully charged 12 Volt lead acid battery, which is what many radios use as a power reference.
<p>
The next thing to consider is that a transceiver can draw quite a bit of power when it's transmitting. My Yaesu FT-857D user manual suggests 22 Ampere, but I've never seen that in the decade it's been in my possession.
<p>
When you purchase a radio, you'll likely discover that it either comes with bare wires, or some random connector that doesn't fit anything else. In many cases I've discovered that people cut off that connector and replace it with whatever standard they've come up with in their shack, but when they take their kit out on a field day, or acquire a new radio, the problem starts all over again.
<p>
Let me suggest a different approach.
<p>
The Anderson Power company, founded in 1877 by brothers Albert and Johan Anderson in Boston Massachusetts, make a range of connectors called the Anderson Powerpole and they come in a variety of ratings, sizes, shapes and colours.
<p>
First introduced as a standard by the ARRL Emergency Communications Course in December of 2000, after previously being adopted by amateur operators in California, the Anderson Powerpole PP15/45 series was selected. The Coordinator for Hawaii State Civil Defense RACES, or Radio Amateur Civil Emergency Service, Ron, then AH6RH, now KH6D has a detailed description on his QSL page on how this came about.
<p>
As a result, the stackable, asymmetric, genderless plugs are in wide use within the amateur community. The plugs are designed to be joined together using various orientations, creating a unique connector to suit your purpose. The Amateur Radio Emergency Service or ARES standard is one such orientation and before you adopt the Anderson Powerpole in your shack, make sure you use their orientation to avoid magic smoke from escaping your equipment.
<p>
Picking a connector is just step one.
<p>
When you acquire a new piece of 12 Volt equipment, you can cut off the connector and replace it with the ARES Anderson Powerpole connector orientation. Many amateurs I know then throw away the unusable connector, or shove it into a box for later.
<p>
Instead, what I do is, terminate the plug that you just cut off in exactly the same way. Essentially, from a visual perspective, you've kept the power cable intact, but inserted a Powerpole join into the lead. As a result you now have a standard Powerpole power lead and you have a new Powerpole adaptor to suit the new connector.
<p>
For that reason alone, I tend to bring a box of spare Red and Black Powerpole connectors to any field day and use the opportunity to spread the love around.
<p>
As I said, the individual plugs come in a variety of colours, I have a selection of eleven in my shack, where for me a different colour means a different voltage or purpose. For example, I've adopted green as the colour for antenna radials.
<p>
One challenge I'd not been able to resolve, until suggested by Ben VK6NCB, was how to avoid plugging a 12 Volt power supply into something that expects say 7.5 Volts. Colour alone isn't sufficiently idiot proof, especially in the dark. Ben suggested that I adjust the orientation of the plugs, preventing connectors of different colours to mate. Looking back, I can't understand why I didn't think of that in the decade I've been using them.
<p>
I will note that there are other Anderson connectors in use. A popular one is the grey double connector, used in portable solar installations and caravans. I'd recommend that you consider if you really want to plug your radio directly into a solar panel or not and choose your connectors accordingly.
<p>
Before you ask, to my knowledge the Anderson Power Company doesn't know I exist, nor did I get compensated in any way to say Anderson Powerpole. It's the ARRL Emergency Services standard and I'm happy to advocate for its use everywhere I go.
<p>
So, whether you're using bare wires, banana plugs, Molex connectors or some other random barrel connectors, consider cutting the lead and inserting Anderson Powerpole connectors.
<p>
When was the last time that you had to do the 12 Volt connector dance?
<p>
I'm Onno VK6FLAB
Listen:
Defining a standard on Contest Scoring
Foundations of Amateur Radio
<p>
Not a weekend goes by without an amateur radio contest or six, each with its own objectives, audience, times, rules, exchanges and scores. When you get bitten by the contesting bug, you'll quickly graduate from using pen and paper to keyboard and screen. That process comes with the inevitable selection of software suitable to both run on your shack computer and log your particular contest since as you'll discover, not all software knows about all contests or runs on every computer.
<p>
When you eventually do arrive at a working solution, you'll reap the rewards of using technology. Contesting software can help in many different ways. From logging your operating frequency and mode to tracking where other stations are active and it doesn't stop there. Type in a partial callsign and your software can suggest which ones it might be. Log a contact and you'll see if your contact is valid within the rules or not. Software can track your activity level and warn if you're exceeding any contest time limits. It can keep track of multipliers and the impact on your total score and at the end of a contest, contesting software can help with submitting your log.
<p>
After you've done this for a while, you'll notice that contest rules and scoring change over time. That brings with it the possibility of your software using old and invalid rules for validation, scoring and other contesting requirements.
<p>
In most cases, software is updated manually by the author to implement the latest rules. This means that authors are required to keep up to date with the rules for all of the contests that their software supports, let alone add new contests.
<p>
There are a few applications that support the idea of a contest definition which suggests the ability for anyone to define contesting rules to use them within the application. Unfortunately their functionality is strictly limited and they are not sufficient to define every contest rule that is in use today. Sadly, flexible as they might seem, they're neither universal nor compatible with each other. One definition, written by one amateur, for one application, cannot be used anywhere else, never mind trying to determine what the latest version is.
<p>
I strongly believe that we need a shared open standard that can serve contest organisers, contest software developers and contest participants. Before I elaborate, I will be explicit in pointing out that the intent is to standardise in a way that makes it possible to document all past, current and future contests and in doing so, provide a collaborative way to share contesting rules between organisers, software developers and contesters, not to mention awards committees and amateur associations.
<p>
So, if such a contest rule standard were to exist, what would it look like?
<p>
Until now, the approach has been to create a list of keywords and values that deal with particular types of rules, things like band start and stop, zone score, valid prefixes, power level, exchange, etc. The result is a growing but always incomplete list of keywords with no means to define any logic. At the moment, all the contesting applications manage any scoring logic internally, requiring that it's updated when any of the rules change. Not only that, the contest organiser has no insight into the mechanism and no means to validate the process.
<p>
As a contest organiser, scoring hundreds if not thousands of logs is a whole different challenge. Many contests do this manually, rely on someone else's software, or if the contest is popular enough, write their own code to manage the process.
<p>
All this effort creates a disconnect between the contester, the organiser and the contest software developers, each using their own definition of the rules of any particular contest.
<p>
A different approach might be to implement specific rules in a universal programming language like say JavaScript, and use those to manage the scoring and validation logic specific to each contest.
<p>
For example, you might define a function that returns the starting and ending time for a contest which gives you a mechanism to detect if the contest is happening right now. A contester could use it to determine when the contest starts and ends, but the same definition could be used by the organiser to determine if a submitted log entry is for a valid time.
<p>
Another might be a function that uses a callsign to determine if it attracts points or not and if it does, how many. Contesting software might use it to change the colour of the screen to indicate an invalid entry, but an organiser might use it to exclude a contact from a log.
<p>
You could have a function to determine if the exchange is valid, or what the next exchange number is, or if the frequency on which the radio is currently tuned to is allowed for a contest.
<p>
You could combine some of these simple rules to determine, for example, if the frequency the radio is on is the same or different since the last contact and if that's permitted or not within the rules.
<p>
As long as the framework in which this standard is defined is extensible, any contest could be defined in this way.
<p>
If it's written well, contest organisers might be able to write their own rules using this standard and everyone can use the same rules for their own needs.
<p>
You might recall that I've spoken about aspects of this problem before and at the time I suggested that an amateur radio standards body would be helpful. Failing that there's nothing stopping a few people collaborating in a discussion about how this might be implemented.
<p>
As an IT professional outside my shack I have some ideas on what's needed and what could give the whole amateur community something useful, but unsurprisingly, I don't know everything. Working together as contesters we might come up with a better result. As a starting point, I've created a repository on GitHub called "amateur-contesting-standard" to start a conversation about this scheme and I would love to read your thoughts and see your ideas on how this might be achieved.
<p>
If you'd like to get in touch, send an email to cq@vk6flab.com or find my callsign on Twitter and GitHub.
<p>
I'm Onno VK6FLAB
Listen:
If you had money, what would your amateur adventure look like?
Foundations of Amateur Radio
<p>
A couple of weeks ago a friend, Ben VK6NCB asked an interesting question in our weekly net. He wanted to know, if money wasn't a concern, what would your ideal shack look like? The answers varied widely from leaving everything as is and using the money to retire, through to purpose built fixed or mobile shacks, with world wide DXCC activation travel and everything in between.
<p>
My own answer was a little different. I envisaged establishing an RF research laboratory and spending my life exploring and investigating the ins and outs of the fundamentals of our hobby. Building software defined radios and building tools to leverage their capabilities.
<p>
As far-fetched as money not being a concern might sound, it's something that a group of radio amateurs had to grapple with in 2019 when their group came into some money. The result is a private foundation with the aim to support, promote, and enhance amateur radio digital communications and broader communication.
<p>
The foundation, Amateur Radio Digital Communications or ARDC uses its resources to provide grants to the amateur community. There's a number of criteria to be eligible to receive an ARDC grant, but you must at least relate to the support and growth of amateur radio, education, research and development. Grants are evaluated on a range of aspirational goals, things like reach, inclusiveness, innovation, social good and others.
<p>
One of the first questions you might ask is how did these people get the money and why are they giving it away?
<p>
To answer that we'll need to travel back to 1981 when Hank, KA6M had the foresight to imagine that Internet-style networking was going to be a thing and requested a block of IP addresses for use by radio amateurs. If you're not familiar, an IP address is like a telephone number, but for a computer. Hank was granted a block of 16.7 million addresses. For decades these were informally administered by a group of volunteers working under the name of AMPRnet and later 44Net.
<p>
In 2011 the group founded ARDC as a California non-profit and officially took ownership of the network space and its management.
<p>
At this point I'll make a slight detour into IP addresses. I promise it's relevant.
<p>
For information to travel to a computer on the Internet it needs to have an address. That address, originally specified using a 32-bit number, a so-called IPv4 address, made it possible to uniquely identify around 4 billion computers. With the explosive growth of computing and the Internet, the world started running out of addresses and in 1998, IPv6 was proposed to solve the problem. It uses a 128-bit number and has space to uniquely identify something like 340 trillion computers.
<p>
In 2018, the ARDC was presented with a unique opportunity to sell some of its increasingly valuable address space, due to IPv4 address scarcity, but soon to be worthless, due to IPv6 adoption. After a year of internal discussion, in the middle of 2019, the decision was finalised and the ARDC sold a quarter of the address block that Hank had been granted back in 1981. On the 18th of July, 2019, Amazon Web Services became the proud new owner of just over 4 million new IP addresses.
<p>
I should point out that radio amateurs haven't ever used more than half of the original block and IPv6 is going to make this no longer any issue.
<p>
So, how much did they make from this adventure?
<p>
Well, each address sold for about $25, making for a lump sum of well over $100 million dollars which the ARDC used to establish its grants program. To round off the story, in 2020, the ARDC changed from a public charity to a private foundation and continues to administer the 44Net and the grants program.
<p>
Their grants list is impressive and inspirational, so check it out on the ampr.org website. While you're there, you can subscribe to the newsletter and read about some of the amazing work that's flowing from the ARDC as a result of its efforts.
<p>
At this point you might be getting all excited about applying for a grant and you should, but I'd like to ask a different question.
<p>
What have you done lately to grow our hobby, to stimulate it, to encourage new people, to innovate, research and learn? What has been your contribution?
<p>
So, if you had money, what would you do with your amateur adventure?
<p>
I'm Onno VK6FLAB
Listen:
How to isolate and by how much?
Foundations of Amateur Radio
<p>
If you connect the antenna ports of two radios together and transmit from one into the other, that would be bad, right? Just how bad would it be and what could you do differently?
<p>
Before I dig in, you might ask yourself why on Earth this question even arises.
<p>
Consider having two radios and one antenna. You couldn't use a T-piece to connect two radios to the antenna unless both were receivers. So, after connecting and disconnecting coax for a decade, you might decide to use a two position coaxial switch instead. Set the switch to one port and the first radio is connected to the antenna, flick it to the other port and you've just avoided swapping coax between radios.
<p>
I'll point out that in most cases a coaxial switch can be used to connect multiple antennas to one radio, or in reverse, connect multiple radios to one antenna.
<p>
When you do start looking for a switch it would be good to test that at no point it connected any two switching ports together, potentially causing the magic smoke to escape from your radio.
<p>
A less obvious issue is that a coaxial switch has a property called isolation. It's a measure of what part of a signal leaks between ports and you'll see the isolation or cross-talk of a switch described in decibels or dB.
<p>
If you recall, a dB is a relative measure. It means that it's something in comparison with something else, in our case, the amount of signal going into one port compared with the amount of signal leaking through to a disconnected port.
<p>
You'd think that in a perfect switch none of the signal would leak through, but it turns out that under different frequencies a switch responds differently, even one specifically designed for switching radio frequencies. It might be that a 1 kHz signal is completely isolated, but a 1 GHz signal is not, which is why when you look at the specifications of a coax switch, you'll see something like "greater than 70 dB isolation at 200 MHz". It's worth noting that the lower the frequency, the higher the isolation, indicating that in the worst case, at 200 MHz, there's 70 dB isolation, but at lower frequencies it has higher isolation, sometimes much higher.
<p>
If you were to transmit into this switch with 5 Watts at 200 MHz, the amount of signal that can leak through would be 70 dB less than 5 Watts.
<p>
You might recall that you can convert Watts to dBm to allow you to do some interesting calculations. As with other dB scales, it's in comparison to something else, in this case a dBm is in reference to 1 milliwatt and 5 Watts is the equivalent of 37 dBm. This means that if you had a switch with 70 dB isolation, you'd start with a 37 dBm transmission, take 70 dB isolation and end up with a -33 dBm signal leaking through. That's the same as 0.0005 milliwatts. In other words your 5 Watt transmission leaks through your coax switch to the tune of 0.0005 milliwatts.
<p>
Is that enough to damage your radio?
<p>
Well, that depends on the radio, but let's put some numbers against it.
<p>
S9 on VHF and UHF was defined in 1981 as -93 dBm assuming a 50 Ohm impedance of your radio.
<p>
So, our leaking signal, -33 dBm, is 60 dB higher than S9. You'd report it as a 60 over 9 contact, a tad excessive, but not unheard of. So by that metric, you should be fine.
<p>
Many, but not all, radios specify the maximum radio frequency or RF power that they can handle. For example, according to the documentation, both the NanoVNA and a Icom IC-706 can each handle a 20 dBm or 200 milliwatt signal without doing damage. That means that your -33 dBm signal should't do any damage to those two devices.
<p>
I'm off to see what the isolation is for cheap 12V relays to see if I can construct a cost effective, modular, remote control antenna switch with lightning detection.
<p>
What are you building next?
<p>
I'm Onno VK6FLAB
Listen:
Smith, the chart to end all charts ...
Foundations of Amateur Radio
<p>
In the time that I've been a radio amateur not a day has gone by without learning something new. Today was no different and this time learning took me both by surprise and delight. I realise that being delighted by charts, since that's what we're talking about, might not be something that comes naturally, but I can highly recommend that you use this as an opportunity to explore.
<p>
So, which specific chart am I referring to?
<p>
The venerable Smith Chart, something which I've seen from a distance many times in the past decade, but never actually understood, or to be honest, even looked at with anything more than a glance and a shudder.
<p>
My first exploration started with a book published in 1969 by the person who developed the chart, Phillip Hagar Smith, an electronics engineer. The book, over 250 pages, is dense and frankly my reading of the first part of the book did not fill me with delight, but based on what I discovered afterwards, I might revisit it.
<p>
The purpose of the Smith chart is to visualise complex mathematical relationships. Instead of filling your worksheet with a litany of calculations, you can draw lines, circles and read the answer straight off the chart.
<p>
For example, given the impedance of an antenna system, determining the standing wave ratio becomes a case of putting a dot on a chart, drawing a circle through the dot and reading the VSWR straight off the chart.
<p>
It gets better.
<p>
If you have a digital Smith chart, like the one shown on a NanoVNA or a RigExpert antenna analyser, you can read the antenna impedance in relation to frequency, use a tuner to change it and see the chart update in real-time in direct response to you changing inductance or capacitance by twiddling the knobs on the tuner.
<p>
One of the main things that a Smith chart solves is to visualise a chart with infinity on it, twice. In radio a short-circuit is one extreme and an open-circuit is another. Coming up with a way to show both those conditions on the same chart is a stroke of genius.
<p>
The chart has evolved over time, but in essence it's a circle with an amazing set of arcs drawn throughout. The very centre of the chart has the number 1.0 next to it. That's the point at which the VSWR is 1:1, the reactance is zero and it's called the prime centre. A dummy load should show up as a dot in that spot, regardless of frequency.
<p>
The Smith chart is normalised. It doesn't matter if you're using a 50 Ohm or a 75 Ohm antenna network system, the middle of the chart is 1.0. Follow the horizontal axis to the right and you'll discover 2.0, that represents twice the resistance. If you're using a 50 Ohm system, 2.0 represents twice that, or 100 Ohm. Go to the left, find 0.5 and that represents half, or 25 Ohm. The far left point on the horizontal axis represents zero Ohm, or a short circuit, the far right represents infinite resistance, or an open circuit.
<p>
Positive reactance, or inductance is shown above the horizontal line, negative reactance, or capacitance is shown below the line.
<p>
Going back to the middle of the chart, you'll discover a circle. All along that circle the resistance is the same, that is, on a 50 Ohm system, all of that circle represents 50 Ohm. If you look directly above the prime centre, you'll discover another 1.0 on the edge of the chart. The arc coming from that point represents an inductive reactance of 50 Ohm all along its path. Similarly, at the bottom of the chart you'll see an arc coming from a 1.0, representing the capacitive reactance.
<p>
Before you pack it in with all this inductive and capacitive reactance, think of it as another attribute of your 50 Ohm antenna system. You don't need to precisely know how it works in order to use it.
<p>
Remember how I mentioned that you could just read off the VSWR from the chart?
<p>
Drop a point on the chart, anywhere is fine. You can read off both the resistance and reactance following the two arcs through that point. If you draw a circle through the same point with the centre at the middle of the chart, the VSWR of that system is the number that you can read, where your circle crosses the horizontal axis.
<p>
Before I go, there are plenty of YouTube videos on the topic, but there are a few that I'd recommend you explore. Among an amazing array of RF educational videos, Rhode and Schwartz made a ten minute presentation called "Understanding the Smith Chart" which walks you through how to read the chart and you don't need the prerequisites to follow along. In Part two of his "Smith Chart Basics" series, Carl Oliver shows how to look up the VSWR in three easy steps and Alan W2AEW has several videos showing the chart in action with several vector network analysers or VNAs and I'd recommend that you look at videos 264 and 314 to get started, but there's plenty more of his handy work to explore.
<p>
If you take away anything from this, it should be that the Smith Chart isn't scary, there's just lots of stuff there, but spend a few minutes looking at it and you'll discover just how useful it can be in your day to day amateur antenna tuning adventures.
<p>
If you've come across other interesting resources on the topic, don't hesitate to get in touch.
<p>
I'm Onno VK6FLAB
Listen:
Can you build an all HF band concurrent WSPR transmitter?
Foundations of Amateur Radio
<p>
It is in my nature to ask questions. It's been hammered into me from an early age and it often brings me new friends, new ideas and new projects. After spending quite some time mulling over my understanding of radio, I came up with this question: "Is it possible to build a single radio transmitter that is capable of emitting a WSPR signal at the same time on all the HF bands?"
<p>
Before we look at the hardware, let's contemplate for a moment what this transmission might look like.
<p>
Imagine a WSPR transmission as a normal audio signal. It sounds like a couple of warbling tones for two minutes. Unpacking it, the audio signal is about 6 Hz wide and sits somewhere between 1400 and 1600 Hz. If you were to draw a power chart of this, displaying the frequencies horizontally and power vertically, you'd see a completely flat chart with a little spike, 6 Hz wide, somewhere between 1400 and 1600 Hz.
<p>
Using an analogue radio, you can play this sound into the microphone or audio port and the radio takes care of transmitting it on the 10m band as a 28 MHz beacon. Tune the radio to 40m and it appears as a 7 MHz transmission.
<p>
The two takeaways are that the WSPR signal itself doesn't change between bands or transmissions and the radio does the heavy lifting to make your WSPR transmission come out at the right frequency.
<p>
Your radio is moving the audio frequencies to the correct amateur band. The electronics in your radio achieve this move by mixing the audio and the tuning frequencies together.
<p>
If you imagine a 28 MHz WSPR signal coming from your transmitter as a power chart, it's essentially silence, except for a little WSPR peak somewhere just off to the right of 28 MHz.
<p>
From a mathematical perspective, the frequency mixer in your radio is performing a multiplication and best of all, you don't need a radio to do this. You could use software to multiply frequencies instead and end up with something that represented their product. If you were to create a power chart of this equivalent multiplication, you'd see a completely flat chart with a little spike near 28.1261 MHz.
<p>
Sound familiar?
<p>
It gets better.
<p>
You can store the result of this calculation in a file as a 28 MHz WSPR signal and you could do this as many times as you want. You could create a file with a 3.5 MHz WSPR signal, one with a 7 MHz one and so-on.
<p>
Since we're talking about shuffling numbers only, you could combine all these calculations, and end up with a single file that had several WSPR signals inside it.
<p>
The chart picture is again mostly silence, just with little WSPR peaks at frequencies suitable for say transmission on the 80, 40, 15 and 10m bands.
<p>
Now all you need is to find a device that's capable of transmitting it.
<p>
Turns out that we have such a device. A PlutoSDR, a software defined radio which I've spoken about before. It's capable of transmitting a 56 MHz wide signal, more than ample for what we're doing. We don't need to use the PlutoSDR to calculate the combined signal either, since we can do all that in advance, because as I said, a WSPR signal doesn't change.
<p>
So essentially, all we'd need to do is generate a file that has all the WSPR signal information at the right frequencies and send it to the PlutoSDR to transmit.
<p>
There are a couple of hurdles to overcome.
<p>
When you multiply two frequencies, you end up with two peaks, one at the sum of both frequencies, and one at the difference between them. One you need, the other you don't, so we're going to need to filter this out, something that your analogue radio circuit also does.
<p>
Another challenge is around sampling rates. The PlutoSDR needs a specific sampling rate and bit depth, so we're going to have to generate our file just so. I'm going to skip past complex numbers and move on to power output, since all the power from the transmitter will be spread across all of the combined WSPR signals we're attempting to transmit, so we're likely going to need amplification.
<p>
There's also the matter of testing before we actually connect this contraption to an antenna and I've glossed over one minor but essential point, the PlutoSDR doesn't do HF.
<p>
So, where does this leave us?
<p>
We can build a proof of concept using 2m and 70cm. Both those bands are native to the PlutoSDR. I'm currently working on generating the actual WSPR signal file to start the transformation process. A friend has some testing gear that could allow us to see what's coming out of the transmitter without polluting the airwaves and of course, at this point this is all still "What-if". I've not actually made this work, but it's keeping me entertained and that's half the fun.
<p>
It gets even better. The Pluto has an FPGA on board, so theoretically at least, we might be able to generate this actual file inside the Pluto in real-time, which opens up a whole other avenue of exploration, but we'll start with crawling before running.
<p>
If you have thoughts on this, or any other aspect of the hobby, please get in touch. You can send email to cq@vk6flab.com or you can find me on Twitter and Reddit with my callsign.
<p>
In the meantime, you know the drill. Get on air and make some noise.
<p>
I'm Onno VK6FLAB
Listen:
What are the rules for calling CQ on a repeater?
Foundations of Amateur Radio
<p>
When you finally get to the point of pushing the talk button on your microphone, after passing the test, receiving your license, getting your radio, building an antenna, digesting the manual, identifying a repeater, untangling its offset, programming those frequencies and keying up, you might be surprised to realise that you're lost for words. Something which I've talked about before.
<p>
Even if you do have something to say, finding a person to say it to will be the next big challenge. Truth be told, the more frequencies you have to choose from, the harder it seems to discover a fellow amateur and with Internet connected repeater networks, your choice appears infinite.
<p>
So, how do you initiate communication on a repeater? Do you call CQ, ask for a signal check, or just kerplunk the repeater to prove that your signal is getting in?
<p>
The very first thing to remember is that you have the exact same rights as every other amateur. No amateur is above any other, though hearing some conversations or responses might give you a different impression.
<p>
Before you embark on a long speech, what you need to remember is that your ability to receive is not usually the same as your ability to transmit. If you're using a low-powered hand held radio that's tuned to a local repeater, you might be comparing your little stubby antenna, inside your home, held at an angle, with that of a high power repeater, with a high-gain antenna bolted to a tower installed on the top of a hill. In other words, you can hear the repeater much better than it can hear you.
<p>
You'll quickly observe that there are amateurs about who have their radio on all day long and they'll often hear every single transmission that hits the local repeater and even random frequencies. Sometimes this means that you'll have a great friend to talk to, other times it means that you'll have a local troll who in their not so humble opinion determines what is permitted and what's not.
<p>
So, to get things rolling, you should follow the KISS principle, an aim championed by the lead engineer of the Lockheed Skunk Works in 1960, Kelly Johnson, "Keep it simple stupid.".
<p>
With keeping things simple, there is a fierce and ongoing debate around the use of the phonetic alphabet on a repeater. With the benefit of experience, having run a weekly radio net for over a decade I'm going to be blunt. When you're identifying yourself to the rest of the community, always use phonetics. Only if you've been acknowledged and you're part of the conversation should you even consider dropping your phonetic callsign.
<p>
The reason is that your first transmissions will be regularly interrupted by others since they're having a conversation and you'll be butting in. Even if a net controller asks for check-ins, you should use phonetics, since you might not be the only one who keys up at the same time. If you and the controller have known each other for years and they recognise your voice, you could consider dropping the phonetics, but don't expect everyone to know who you are from a single letter getting through. Some people are better at this than others.
<p>
Whatever you do, don't barge in with a whole story until you've been acknowledged and the microphone has been handed to you. After all, this is a public shared space.
<p>
The next thing to consider is the audience you're talking to. If the repeater is just local, then the people within range are likely to expect your prefix and know who you are, so just your call might suffice, but if you connect to a network, that's not likely to be true. If you want to actually talk to anyone, you can call CQ, but if you just want to let people know you're there, you can say your callsign followed by the word "listening".
<p>
If you want to speak with a specific individual on the other hand, you can call them using their phonetic callsign, either with or without the CQ. Also consider they might be on the other side of their shack working hard at attempts to avoid sniffing solder fumes and take a moment to get to the microphone.
<p>
In other words, what you say on your repeater depends on what result you want and who else is there. Sometimes there will be a mismatch between the two, just saying your callsign might initiate an hour long conversation, and calling CQ might give you the local troll telling you to go away.
<p>
Don't let that dissuade you. Even with years of practice, sometimes the results are unexpected.
<p>
Talking on a repeater is like being invited to a party. There are going to be people you know, people you want to know and people you never want to meet again.
<p>
So, be considerate, listen more than you talk and be deliberate in your intentions and you'll be fine.
<p>
Thanks to Sandip EI7IJB for the question, "What are the rules for calling CQ on a repeater?" If you have other burning questions, get in touch and ask. I'll try to give you a coherent answer.
<p>
I'm Onno VK6FLAB
Listen:
The Thunder and Lightning that destroyed my station ...
Foundations of Amateur Radio
<p>
The other day I was woken by the sound of a thunderclap. It was shockingly loud and came out of the blue. A few moments later, it happened again. I exploded out of bed, rushed to the shack, disconnected the beacon power and switched the antenna coax to "safe".
<p>
After breathing a sigh of relief, everything went dark and with it came the distinctive sound of the sudden death of the uninterrupted power supply taking with it my workstation.
<p>
With nothing else left to do, I reported the outage to the power company, went back to bed, pulled the covers over my head, snuggled in and surprisingly, slept pretty well despite the barrage of water hitting my QTH. The next morning the power was back on and I discovered that one of the residual current devices, the one that powered most, if not all, the wall sockets had tripped. I reset it and much to my surprise, most of my QTH came back to life.
<p>
I say most, because after breakfast I had a moment to switch on my radios and see what, if any, damage there was. I could hear and trigger the local repeater, but HF was strangely dead. I could hear the coax switches turning on and off, but the SWR on the antenna was high and it didn't appear that the antenna coupler was doing anything. It's powered remotely using a device called a Bias-T. You use two of them to transport a power supply voltage along your antenna coax. In my case, I inject 12 Volts in my shack, and extract the 12 Volts at the other end near the antenna where it powers the antenna coupler.
<p>
Occasionally the antenna coupler needs a reset, so I removed the power, waited a bit and reconnected. Still no response from the coupler, so I disconnected the power and left it for another time.
<p>
A few days later I had a moment to investigate further, so I went outside to check out the antenna and coupler. Both looked fine. I removed and reinserted the power, heard a click, but wasn't sure since a car came barrelling down the road at the same time, so tried again and heard nothing.
<p>
At this point I decided that this warranted a full investigation and started putting together a mental list of things I'd need. I wanted to test the coupler when it was isolated, I wanted to do a time-domain-reflectometry, or TDR test, to see if anything had changed. This test uses the RF reflection of a cable to determine its overall length and any faults like a cable break, high or low resistance and any joints. If you have a Nano VNA or an antenna analyser, you can do this test. It did occur to me that I didn't have a baseline to compare with, so that was disappointing, but I added it to the list.
<p>
First thing to test was to check if the radio had been affected. I turned it on, did the same tests and discovered that the Bias-T was still disconnected, which could explain why I didn't hear a click when I tested a second time. Armed with a level of confidence around power, I tried again to trigger the antenna coupler and got nothing, dread building over the potential loss of a radio in the storm, I set about swapping my HF antenna to another radio.
<p>
At this point I was reminded of an incident, 37 years ago, as a high school student during a class outing. My wonderful and inspirational physics teacher, Bart Vrijdaghs, took us to the local University where the head of the Physics Department of the University of Leiden gave us a tour of their facilities. He took us into a student lab full of oscilloscopes and tone generators and set-up a demonstration to show us how you could generate Lissajous figures. He was having some trouble making it work and with the impertinence reserved for teenagers I quoted a then popular IBM advertisement from 1985, "Of Je Stopt de Stekker Er In", which loosely translates to asking if he had plugged it in.
<p>
I can tell you, if looks could kill, I wouldn't be telling this story.
<p>
Suffice to say, it wasn't. Plugged in, that is.
<p>
Back to my HF antenna.
<p>
Yeah. It was already plugged into the other radio, so, unsurprisingly it was unable to send any RF to, or from, the first radio, much like some of the advanced telepathic printers I've had the pleasure of fixing during my help desk days a quarter of a century ago.
<p>
After all that, I can tell you that HF seems to work as expected. The beacon is back online and I have some work ahead of me to create some baseline TDR plots and perhaps a check-in, check-out board to keep track of what's plugged in where.
<p>
That and looking for another UPS, since keeping the computer it's connected to up and running, at least long enough to properly shut down, would be good.
<p>
What other lessons can you take away from lightning hitting nearby?
<p>
I'm Onno VK6FLAB
Listen:
When should I go on air?
Foundations of Amateur Radio
<p>
When you obtain your license there's a whole lot of learning to be had before you even get started with your first transmission, but when you get there you'll discover that learning has just begun and the rest of your life will be beset with challenges, quests, discovery and dawning understanding.
<p>
One of the early and recurring questions is around the best time to be on air. Before I get into the why, the answer is, right now.
<p>
This interminable question will continue to haunt you throughout your life, and the most pressing answer will be shaped around the missed opportunity. You'll discover tools that assist with predicting propagation, web-sites that explain what the various layers of the ionosphere do and how they affect your ability to use radio to make contact with other amateurs.
<p>
There's learned discussion around testing and tracking propagation, special modes that help create your own maps for your own station and you'll discover an endless supply of experts who will advise you when you should power up your transceiver and call CQ.
<p>
Whilst I've only been an amateur for a short time. In the decade to date I've learnt one thing about propagation. Despite all the tools, the discussion, the maps and forecasts, there is no substitute for actually getting on air and making noise. Over the past while I've been watching the propagation from my own shack using a 200 milliwatt beacon and I've discovered that running 24 hours a day, every day, well, almost every day, my signal gets to places far beyond my wildest dreams.
<p>
I have also discovered trends. That is, the average distance of the signal reports is increasing over time. This isn't a linear thing, not even a recurring thing, much like the ebb and flow of the tides, varying from day to day, a little bit at a time, inexorably making your shoes wet when you least expect it.
<p>
While to some extent we've tamed the prediction of the tides with complex and interrelated cycles, discovered by using Fourier transforms, we're no-where near achieving this level of sophistication for the ionosphere and its associated propagation.
<p>
Just like predicting a specific wave is still beyond the capabilities of a tide table, predicting the ability of a radio wave to make it from your antenna to that of another amateur is beyond any tool we have today.
<p>
Another way to look at predicting the complexity associated with the ionosphere is comparing it to weather forecasting. We have national forecasting bodies, with millions of sensors, super computing cycles that dwarf most other research, a global network of satellite sensors, roughly a quarter of which have some form of earth sensing capability, transmitting terrabytes of data every day and still we cannot determine where on Earth it's going to rain tomorrow.
<p>
The ionosphere, whilst it's being monitored, is not nearly as well resourced. It's not nearly as visible to the average person as the packing of an umbrella and the political perception of need is nowehere near as urgent as getting the weather right.
<p>
So, absent accurate forecasting, finding a better way to determine when to get on air is required. That said, I've discovered that regret is the biggest motivator to get on air. The day after a contest when a friend made a contact with an amazing station, or the lunch break where I didn't power the radio on to discover a random opening to a clamouring horde of calls looking to make contact.
<p>
So, my best advice to you is to get on air whenever you can. You might not make a contact every time, but you'll discover what the bands look like right now and you'll have the chance of hitting the jackpot with a rare contact and truth be told, I think your chances of making a contact are higher than winning the lottery.
<p>
When you do take that step, you'll start discovering the ebb and flow of the bands, discover the characteristic sound that each band makes and what a band sounds like when it's open and when it's not. You'll hear stations far and wide, discover that while there are trends in propagation, there are no rules. From one moment to the next, you'll discover the thrill of hearing something unexpected.
<p>
One thing to consider, if you get on air for the sole purpose to make contacts, you're likely going to be disappointed. It's like fishing. Most people don't get up at some crazy hour, sit on a damp jetty, freezing parts of their anatomy off for the sole purpose of catching fish.
<p>
So, get on air and make some noise, today.
<p>
I'm Onno VK6FLAB
Listen:
Augustin-Jean Fresnel, Zeppelins and a picket fence ...
Foundations of Amateur Radio
<p>
In our hobby we regularly invoke line of sight when we discuss the VHF and higher bands. It's a simple concept to help describe when two transceivers can hear each other. The process evokes an image of a beam of light travelling unobstructed between the antennas at either end. Some might picture a laser, others a flashlight, both are useful to become familiar with some of the concepts.
<p>
If there's a pole between the two, a laser beam, unless it's particularly powerful, won't go through to the other side. A flashlight beam on the other hand might fit around the pole and still be visible at the destination. That illustrates that objects can get in the way of a signal, reducing strength and sometimes blocking it entirely, but it's not the only effect at play.
<p>
Imagine a building with a mirror glued to its side. If you shine a laser at an angle at the mirror, you can reflect the light off the mirror and essentially still land on target. This is useful if you want to avoid an obstacle directly between you and your destination.
<p>
The reflected light travels a different and slightly longer distance than direct light would, but if there's no obstacles, both will arrive at the destination.
<p>
This is an example of a multipath, where the same signal arrives at its destination using multiple different paths.
<p>
If you've ever used HF radio, making a contact on the other side of the planet, it should come as no surprise that radio waves travel in more than just straight lines. Depending on frequency, radio waves can be affected by phenomena like ionospheric reflection and refraction, atmospheric ducting and even bounce off water, the ground, mountains, hills and objects like buildings, aircraft and even water droplets, along their path.
<p>
Each of these cause a radio signal to take multiple paths to arrive at the destination.
<p>
It gets better.
<p>
A radio signal that travels along a different path takes a measurable difference in time to get to its destination when compared with another path for the same signal. From a radio signal perspective, this difference in time is also known as a phase shift.
<p>
Now consider a single radio signal that travels along two paths, just like our laser beam and mirror. If you imagine a radio signal as a sine wave, you can draw the two signals on the same chart. They will be in lock-step with each other, since they're the same radio signal, but they won't be on the same place on the chart. In relation to each other they'll be shifted along the time axis, since one took longer than the other to get to the destination.
<p>
At the destination, the receiver hears a combination of both those signals. They're added together. That means that what's sent and what's received are not the same thing and why it's a great idea to use phonetics in radio communications. In some cases the two signals help and strengthen each other, they're said to interfere constructively, and sometimes the signals hinder and cancel each other out, or interfere destructively.
<p>
Said in another way, a radio signal can arrive at a receiver along multiple paths at the same time. What's heard at the receiver is essentially a cacophony, caused by each slightly different path. Since the signals are essentially all the same, some of these signals reinforce each other, where some cancel each other out.
<p>
This effect isn't absolute, since the different path lengths aren't all exact multiples of the wavelength of the signal, they're all over the place, but there will be groups of paths that help and groups that hinder. This phenomenon was first described by Augustin-Jean Fresnel on the 14th of July, 1816 in relation to light and we now call these groups, Fresnel zones.
<p>
Fresnel zones are numbered, one, two, three and up. The first or primary Fresnel zone is the first group of radio signals that helps strengthen the signal, the second zone is the first group of signals that hinders. The third zone is the second group of radio signals that helps and so-on. Odd helps, even hinders.
<p>
I should point out that a Fresnel zone is three dimensional. The primary Fresnel zone essentially has the shape of a Zeppelin stretched between the source and the target. The secondary zone is wrapped around the outside of the primary zone like a second skin, but it's thicker in the middle.
<p>
In practical terms, what this means in point-to-point radio communications is that your antenna needs to be located in a place where most of the signal arrives. The rule of thumb is that the primary Fresnel zone needs to be at least 60% clear, but ideally 80%.
<p>
If you're in a situation where a receiver is moving, say in a car, you can imagine that your antenna is moving in and out of direct line of sight to a transmitter, but it's also moving between the various Fresnel zones. If you were to move your antenna from the first Fresnel zone to the second and then the third, the signal would be strong, then weak, then strong again.
<p>
If your receiver is an FM receiver and it's moving from the first zone to the second, it could fall below a threshold and the signal would effectively vanish. Continue to move from the second into the third zone and the signal would sound like it suddenly reappeared as it climbed above the threshold. Do it fast enough and the signal sounds like it's stuttering.
<p>
That stuttering has a name. In amateur radio we call it picket fencing or flutter and it's commonly heard in mobile situations on FM transmissions on the VHF and higher bands, but it can be caused by other changes in propagation distance, for example an antenna moving in the wind. The higher the frequency, the less movement is needed to experience this.
<p>
To add to the fun of radio, the same threshold effects, actually called the FM capture effect, can be caused by other phenomena, like two stations of similar strength on the same frequency, or interference from the electronics in your vehicle.
<p>
And finally, I should point out that the higher the frequency, the smaller the Fresnel zones, and the more susceptible to an object in the path a signal is, but you already knew that, a pole will block a laser beam, but not a 2m conversation on the local repeater.
<p>
So, line-of-sight isn't just a straight line, it's a whole lot more fun.
<p>
I'm Onno VK6FLAB
Listen:
The Science of Amateur Radio
Foundations of Amateur Radio
<p>
The amateur radio community is as varied as humanity across the globe. It represents an endless supply of ideas and experiments that continue to attract people looking for something new and exiting.
<p>
On the face of it, our hobby is about radio and electronics, about propagation and antennas, about modes and contacts, but if you limit your outlook to those topics you'll miss out on a vast expanse of opportunity that is only just beginning to emerge.
<p>
Until quite recently, computing in amateur radio was essentially limited to logging and contest scoring. It has evolved to include digital modes like PSK31 and the advent of smaller, faster and cheaper computers in the home has brought the possibility of processing unimaginable amounts of data leading to modes like WSPR and FT8.
<p>
In the past I've spoken about how amateur radio means different things to different people. Making contact using a digital internet enabled repeater is sacrileges to one and manna from heaven to another. Between those two extremes there is room to move and explore. Similarly where one uses valves, another expects an integrated circuit. One wants low power, the other wants every Watt they can lay their hands on. Contesting versus rag chewing, nets vs contacts, SSB vs. CW, FT8 vs. RTTY. Each of these attracts a different part of the community with different outcomes and expectations. For some it's about antenna building, others going portable, climbing a mountain, or setting up in a park.
<p>
Those are all traditional amateur activities, but the choice and opportunity don't end there.
<p>
The longer I play with computers the more I see a convergence in the world, a coming together of technologies and techniques. I've talked about some of this before when in 1994 I produced a competition broadcast promotion for the radio station I was working at, using just a computer in the era of reel-to-reel tape and razor blades. My station manager couldn't quite put his finger on what was different, but with hindsight it represented a landslide change in how radio stations have operated since. Mind you, I'm not saying that I was the first, just the first in that particular radio station.
<p>
In many ways computing is an abstract effort. When asked, I like to express it as designing something intangible in an imaginary world using an made up language and getting paid real money to make it happen, well, numbers in my bank account at least.
<p>
Within that context, amateur radio is slowly beginning to reap the rewards that come from the exponential growth in home computing power. While the majority of humanity might use the vast amount of CPU cycles to scroll through cat videos online, that access to processing power allows us to do other things as well.
<p>
For example, right now I'm playing with the dataset that represents all the WSPR spots since March of 2008. As of now there are around four billion rows of contacts, containing data points like a time-stamp, the transmitter, the receiver, the signal strength, location, direction, and more.
<p>
As part of that investigation I went looking for documents containing the words "RStudio" and "maidenhead", so I could consider creating a map in my statistical tool that allowed me to represent my dataset. In making that search I discovered a thesis by a mathematician who was using the reverse beacon network in an attempt to predict which station could hear which transmitter at what time.
<p>
In reading the thesis, which I opened because I was looking for an example on how to convert a maidenhead locator into geo-spacial data types in R, a popular statistics platform, I discovered that the author didn't appear to have much, if any, amateur knowledge or experience, but they approached their task, attempting to predict as a mathematician what we in our community call propagation, based on a public dataset, downloaded straight from the reverse beacon network, created by amateurs like you and I.
<p>
This interaction between science and the amateur community isn't new. Sometimes it's driven by science, other times it's driven by amateur radio. There's a team exploring the ionospheric prediction models that we've used for decades, popularly referred to as VOACAP or Voice of America Coverage Analysis Program, based on multiple evolutions of empirical models of the ionosphere that were first developed in the 1960's, headed by both a scientist and an amateur, Chris KL3WX.
<p>
With the advent of WSPR and the associated data collection some experiments have started to compare the reality of propagation as logged by WSPR to the predicted propagation as modelled by VOACAP. One such experiment happened in 2018 where Chris and his team at HAARP, the High-Frequency Active Auroral Research Program, set out to make transmissions at specific times and frequencies, using the amateur community logging of WSPR spots to compare their transmissions to the predictions.
<p>
Interestingly they did not match. Just think about that for a moment. The tool we love and use all across our community, VOACAP, doesn't match the reality of propagation.
<p>
My own playing with WSPR data is driven by the very same thing that I use to be a better contester, a burning curiosity in all things. My VOACAP prediction experience has been poor to date. Setting up my own WSPR beacon is the first step in attempting to discover what my actual propagation looks like, but in doing so, it's also a possible contribution to the wider challenges of predicting propagation based on a dataset with four billion spots. One such approach might be to create an ionospheric prediction map based on actual data and compare that to the models as well as the published space weather maps and combining these efforts into a machine learning project which might give us the next generation of ionospheric prediction tools, but only time will tell.
<p>
No doubt I will have to learn more about statistics and machine learning than I expect, but then, that's half the fun.
<p>
So, next time you think of amateur radio as being limited to valves, transistors, soldering, antennas and rag chewing on HF, consider that there might be other aspects to this hobby that you have not yet considered.
<p>
What other research are you aware of that relates to amateur radio?
<p>
I'm Onno VK6FLAB
Listen:
The art of troubleshooting the digital world.
Foundations of Amateur Radio
<p>
The lure of digital modes and the opportunities they bring are enough to tempt some amateurs to begin a journey into integrating their radio and computer to make a new world come to life. This isn't without pain or challenge, but the outcomes are so enticing that many embark on this adventure every day.
<p>
As a person who has made this trip it's heart warming to see the joy writ large on the face of an amateur who makes their first FT8 contact on a home brew wire dipole rigged together on a Sunday afternoon to take advantage of the latest opening on the 10m band.
<p>
On the flip side, it's heart breaking to see an amateur falter at the first hurdle, attempting to make their computer talk to their radio and giving up because it just won't work. At first this attitude bewildered me in a community of experimenters, but over time I've come to understand that sometimes an analogue approach isn't suited to the digital world. There isn't really a place where you can attach your multimeter and see why the serial connection isn't working, nor is there any universal document that can walk you through how to set things up.
<p>
So, for you, if you're in a place where you've all but given up, let me see if I can find words to encourage you to keep trying. I'll skip the propaganda about going digital and move straight to making it work.
<p>
This might come as a surprise, but in the digital world, things are built in complex layers of interdependence. Said in another way, using an analogy, to turn on a light you need flick a switch, which depends on power to the switch, which depends on power from the fuse box, which depends on power from the street, which depends on power from the substation and so-on.
<p>
If you flick the switch and the light stays off, you need to figure out which part of the chain failed. Did it fail at the bulb or at the substation? If the street is dark, do you need to check the fuse box or the bulb? That's not to say that either, or even both, can also be faulty, but there's no point in checking until the street has power.
<p>
From a fault finding perspective, the number of variables that you have control over, in the case of a light bulb not switching on, is strictly limited. You can control the bulb and the fuse and in most cases that's about it, the rest of the chain is outside your direct control.
<p>
In attempting to make a computer talk to a radio you can be forgiven in thinking that the level of complexity associated with such a trivial task is just as direct and straightforward. Unfortunately, you'd be wrong. It's not your fault. A popular slogan "Plug and Play" made people think that computers were easy to use and control.
<p>
The truth is a far darker reality. One of the hidden sources of frustration in the digital world is the extreme level of complexity. In our quest to standardise and simplify we have built a fragile Jenga tower of software that can collapse at any point. Most of the time this is completely invisible but that doesn't cause it to be any less real. Computers are simple, but only if you control the environment. And when I say control, I mean take ownership of each change.
<p>
Updating the operating system? Installing a new application? Adding a new peripheral? Changing location? All these things, innocuous as they might seem, can fundamentally alter the behaviour of your environment.
<p>
As an example, consider the location of your device. Let's say that you changed the location of your computer, either physically or via a preference. All of a sudden your Wi-Fi network stops working. The one that you used for years. Turns out that changing location changed the Wi-Fi driver to stop using a particular channel, not permitted in your new location. If you're curious, this happened to me last week.
<p>
The point being that troubleshooting is about controlling change in that fragile environment.
<p>
So, when you're trying to figure out how to make your serial connection work, you need to stop fiddling with everything all at once and change one thing at a time. Discovering the layers of dependency makes this difficult at times, but not impossible.
<p>
For example, a working serial connection requires that both ends are physically connected, speaking the same language at the same speed. That depends on the radio being correctly configured, but it also depends on the computer having the right drivers installed. It also depends on the software you're using being configured correctly to talk to the right serial device and the operating system giving your software permission to do so. It depends on the software using the right radio mode and it depends on the radio being switched on.
<p>
Now, imagine the serial connection "not working".
<p>
Do you check the radio mode before you check if the radio is turned on?
<p>
What about the physical connection?
<p>
When you're troubleshooting, you cannot just look at the error message on the screen and follow that path. You need to ensure that all the underlying things are working first. You don't check the bulb until there's light in the street. Same thing. No need to worry about the error until you've discovered that the radio is on, the cable connected correctly, the driver installed correctly, the speeds set right and the mode configured properly. If and only if that's all correct, then look at the error.
<p>
This becomes harder if it worked yesterday. What changed between then and now? Did your operating system do an update? Did your radio forget its settings? Did the cat jump on your desk and dislodge a cable overnight? Is there an earth fault that caused the serial connection to cease working?
<p>
Sometimes, despite your best efforts, you cannot find the problem.
<p>
At that point you need to take a step back and think about how to prove that something is working in the way that you think it is. Multimeter to a light bulb to check continuity - style. In the case of a serial connection, what can you use to test the link if your favourite tool doesn't work or stopped working suddenly?
<p>
I've said this before, but it bears repeating, since it's not obvious.
<p>
Troubleshooting is all about discovering and controlling change.
<p>
Pick one thing to test, prove that it's correct, then pick the next. Eventually you'll come across a "Duh" moment. Don't sweat it, we've all been there. Now do it again!
<p>
What's your best troubleshooting moment?
<p>
I'm Onno VK6FLAB
Listen:
How far can you go?
Foundations of Amateur Radio
<p>
Antennas and propagation are the two single most discussed topics in our hobby, that and how an FT8 contact isn't real. Not a day goes by without some conversation about what antenna is the best one and by how much? In my opinion it's a futile effort made all the worse by so called experts explaining in undeniable gobbledegook, or sometimes even using science, just how any particular antenna is a compromise.
<p>
The truth is that most conductive materials radiate to more or lesser degree. Sometimes there is enough of that to make it outside your backyard into the antenna of a fellow hobbyist. To make a point, as is my wont, over the past months I've been conducting an experiment. It's the first in a series all related to antennas and propagation. As has been said, the difference between fiddling and science, is writing it down, so this is me writing it down.
<p>
I'm using the tools available to me to explore the various attributes of my station and how it affects what's possible. I will observe that this is within the dynamic nature of the environment, so the solar cycle, solar events, thunderstorms and noise are making an impact. No doubt I'll create a visualisation that links some of those extra variables, but for now I'm just noting that these external events affect what I'm doing.
<p>
You might recall that I took delivery of a WSPR beacon a few months ago. If you're unfamiliar, WSPR or Weak Signal Propagation Reporter, is a tool that allows a station to transmit a time synchronised signal on a specific frequency, so other stations can look for, and attempt to decode it. Think of it as a timed Morse code signal and you'll have a pretty close understanding of what it does.
<p>
The beacon I purchased was a 200 milliwatt, ZachTek 80To10 desktop transmitter, built by Harry, SM7PNV. It can operate on all the HF bands I'm licensed for and can run all day, every day. It's time-synchronised using a supplied GPS antenna and powered by a Micro USB cable. It's currently connected to my vertical antenna.
<p>
That vertical antenna is a homebrew helically wound whip, tuned for the 40m band, clamped to the side of my metal patio roof. It's fed by an SGC-237 antenna coupler which is held by magnets to the roof. A 75 Ohm, RG6 quad shield coax cable, about 20m long, left over from my satellite dish installation days, is connected via several adaptors and coax switches to the beacon.
<p>
This is not a fancy set-up by any stretch of the imagination, but it's my station and what I use to get on air to make noise and that's the whole point of this exercise. You might recall that one of the reasons I want to learn Morse is so I can hear an NCDXF beacon and know which one I'm hearing on my own station. In many ways, this is a different way to approach the same problem.
<p>
Said plainly, "How do I determine what propagation is like for me, right now, on my own gear?"
<p>
There are countless tools available, from the Voice of America VOACAP propagation prediction, through the graphs and charts on clublog.org to the Space Weather Services run by the Bureau of Meteorology in Australia.
<p>
All of these tools have one thing in common, they don't use your own gear.
<p>
Unsurprisingly, you're likely to wonder what it is that I can achieve with a mere 200 milliwatt transmitter and a vertical. Turns out, quite a lot. As of right now, my WSPR beacon has been heard multiple times over the past three months in the Canary Islands, over 15 thousand kilometres away. The Watts per Kilometre calculation puts that at over 76 thousand kilometres per Watt, not bad for a little amateur station located in the middle of a residential suburb. Did I mention that this was on the 10m band?
<p>
I was asked if I would put a pin in my DXCC map, tracking the countries for each of these WSPR reports and my answer to that is "No". This is not a contact, this is a propagation ping. I suppose that I could, if I really wanted to argue the point, which I don't, use a pin if I had a reciprocal report from the other station within a set period of time, but that's not why I'm doing this. The purpose of this exercise is to discover what my station is capable of, what propagation is like, how it changes over time, how uniform my radiation pattern is and how much of the globe can hear my signal.
<p>
One observation to make is that much of the West Coast of the United States is a similar distance away from me, but so far there are no reports from that continent. As a quick and dirty test, I'm using my Yaesu radio and 5 Watts for the next day to see if this is an edge case, or if there is something else going on. For example, my house has a peak metal roof, to the West of my antenna. Is it possible that it's affecting the radiation pattern, or is there something else going on, like the neighbour's house that sits to the East?
<p>
For all I know the noise floor in the Canary Islands is significantly better than anywhere in the USA, but only time will tell.
<p>
I've recently taken delivery of a multi-band vertical antenna which I'm planning to use to replace my current vertical. The main reason being that my antenna coupler cannot tune with 200 milliwatts and to do band-hopping I'd have to re-tune manually each time, not something that is sustainable 24 hours a day.
<p>
No doubt that change will bring other discoveries, but then, I'm keeping track.
<p>
The intent of all of this is that you can experiment with your own station, test ideas, trial a set-up, keep a log and discover new things that your station presents to you. Amateur Radio is never just about one thing, it's always a dozen different things, all at the same time.
<p>
What are you going to discover next?
<p>
I'm Onno VK6FLAB
Listen:
After the chaos ... building the ideal shack
Foundations of Amateur Radio
<p>
One of the first questions a new amateur asks is "Which radio should I buy?" It's a topic I've discussed at length and the answer "It depends." is unhelpful without doing more research, but after you've done the work, you'll be able to answer it for yourself.
<p>
A question that is just as important, but not asked nearly enough, frankly, I've not heard it in the decade I've been part of this community, is: "How should I build my shack?" The answer is just as useful, "It depends."
<p>
So, let's explore what precisely your shack design depends on. Let me start with pointing out that I'm not here to give you answers, you can watch hundreds of YouTube videos, read a gazillion web-pages and get no closer than discover how others have answered this question. It wasn't until recently that I understood that it was a question at all, but airing my frustration at the level of dysfunction of my shack unearthed it and in attempting to answer my own question, I started to explore the landscape.
<p>
As with choosing a first radio, one of the very first answers you need for yourself about the ideal shack is: "What do you want to use it for?"
<p>
That in and of itself is not enough. I had an answer for that, I want to operate my weekly net, I want to do casual HF contesting, have a beacon running and have space for experimentation. It wasn't until Ben VK6NCB suggested that I dedicate a single radio to the weekly net and the contesting and use the other for experimentation, that I discovered that this wasn't going to work for me.
<p>
I want to be able to use both my radios at the same time, in a so-called Single Operator Two Radio setup, or SO2R. This will allow me to extend the boundaries of my comfort zone and in doing so, will give me plenty of new things to learn.
<p>
So, the question: "What do you want to use your shack for?" is probably the single most important thing you need to discover. If you're like me, the obvious answer is: "Everything!", but reality soon sets in and you might start to create an actual list of things that you want to do. Prompted by Ben's suggestion, I was able to articulate for the very first time something that I didn't want to do. I didn't want to set a radio aside for experimentation. So when you're considering what you want to achieve, also think about what you don't want.
<p>
For example, I have no interest in using the 6 meter band at this time. Not because it's a bad band, far from it, it's because I'm not permitted to use it with my current license. Same for the 23 cm band. This means that I don't have to find ways of making my shack accommodate those two bands. My current license permits me access to precisely six bands and the station I'm building only needs to access those bands at the moment. That brings me to the next question for the ideal shack design.
<p>
"How long do you expect the layout to last?"
<p>
For example, are you going to build a new building for your shack, for the next 50 years, or is it something that's going to last for the weekend? Is your shack going to be moved, or is it something a little more permanent? Are you going to change your needs and should you incorporate some of that into your design, or are you perfectly happy with what you're doing today? You have to remember, this is your shack, not mine, not your friends, yours. It means that it needs to accommodate what you want.
<p>
The next question, boring as it might be, "How much money are you going to spend?"
<p>
Building a whole new shack out of a catalogue is perfectly fine, but you might discover that the gear you have today is ample to get your shack started. You might leave space for a different piece of kit, or you might decide that the shack needs changing when a new shiny piece of equipment arrives in a nondescript brown box.
<p>
Some other things to consider are, "What operating actually looks like?"
<p>
I've seen shack videos that look like a tour through a radio museum with more radios than I have keys on my keyboard, sometimes all connected, other times, just stored on shelves to look at.
<p>
Are you going to have more than one radio operating at the same time and if so, how are you planning to control them? How many antennas are connected to this shack and how do you track which antenna is connected to which radio?
<p>
What are you going to do about power? Does everything run on mains power, or are you going to build a 13.8 Volt supply for all your gear?
<p>
Where are you planning to put computer screens, what about keyboard, mouse, Morse key and antenna switching controls? In other words, "What do the ergonomics of your shack look like?"
<p>
Remember, there is no right answer. The answer you come up with is yours and yours alone. Look at things that work for you and take note of things that make you wince when you see it in another shack somewhere. That's not to say that you should be dismissive, rather, use the opportunity to ask the shack owner why they made that choice. Who knows, it might cover something you hadn't considered yet.
<p>
So, what does your ideal shack look like?
<p>
I'm Onno VK6FLAB
Listen:
In the beginning there was chaos...
Foundations of Amateur Radio
<p>
Over the weekend I learnt to my chagrin that my shack was not ready for the contest I decided to participate in for an hour. Truth be told, it was probably me who wasn't ready, but I'm going to blame my shack, since it can't argue and besides this is my story.
<p>
It started off with turning on the HF radio. That involved turning off my 10m WSPR beacon which is transmitting its little heart out 24 hours a day into the one vertical antenna it shares with my HF radio.
<p>
Turning off the beacon was simple enough, reach into the mass of cable and dig out the USB power lead that plugs into the beacon. Then follow the antenna coax to the correct switch. Whoops, that's the GPS coax, the other one, there's the switch, now switching it to the HF radio.
<p>
Why didn't the sound change, actually, come to think of it, what sound? Hmm, the audio is going into, nothing, actually, it's going into the audio mixer that's turned off. Turn that on. Then audio at last, nope. Hmm, oh wait, the audio needs to go from the HF radio, not the VHF radio that's configured to do some audio spectrum recording. Turn off the Raspberry Pi at the same time, since there's no more audio going into that and who needs more potential noise? Locate the two audio plugs that go into the radio audio adaptor, disconnect the Pi audio, connect the radio audio, now, which one is the microphone?
<p>
Now I've got it all plugged in, still no audio. Hmm, two of the mixer channels are muted. Turn on one, radio goes into TX, that's not good. Turn it off, radio stops transmitting, sigh of relief. Turn on the other channel, finally hear some squeaky sounds. Ahha, it's coming from the headset.
<p>
Don the headset, now I've got glorious mono in my brain. Test the microphone, nothing. Hmm, ah the switch on the microphone lead. Now I've got RX and TX going. Yay, victory!
<p>
Now turn on the computer so I can do some logging. Fire up my trusty, wait, which tool? The one I normally use for casual contesting hasn't seen a new version since the author became a silent key, no idea if the rules for this contest are still current, fire up the next one, that needs a brand new configuration file, but that means reading the manual and I've got more important things to do.
<p>
Try another one, Yes, that's got the rules ready to go. No idea if the rules are current, but at least there's no configuration file to contend with.
<p>
At this point I'm two hours into my one hour contesting window and I have to stop. Haven't even tuned the antenna and I'm already out of time.
<p>
Hmm, this shack is rigged.
<p>
Wonder who I should blame for that?
<p>
Some days all good intentions come together. Other days they don't. There's always the next contest.
<p>
Lessons learnt, my shack needs a serious rethink on how best to set it up so I can operate daily, experiment and accommodate a casual contest. Looks like I'm off to the hardware store for some brackets and my documentation clearly needs updating, actually, truthfully, needs writing.
<p>
I'm Onno VK6FLAB
Listen:
Planning for an emergency...
Foundations of Amateur Radio
<p>
Identifying the problem is the first step in fixing it and with that I want to talk about emergencies. One of the very first things I was told about our amateur radio community was that we're here for when emergencies happen. Our purpose is to communicate, so in a crisis, we can assist by supplying communication to the situation.
<p>
I've talked about some of this before. Preparedness in the way of on-air training by contesting, in getting gear ready and even exercises for when this occurs. There are amateur clubs dedicated to putting up repeaters for just such an eventuality.
<p>
Recently there was a local news item about radio amateurs banding together, sending gear to fellow amateurs who were hit by severe flooding that wiped out their shack and with it their ability to communicate.
<p>
Another event was a friend who lost a big chunk of his shack when his basement flooded.
<p>
Across Australia and in other parts of the world in recent times we've been witness to the most devastating fires that destroyed entire towns and communities, taking with it infrastructure, communications, not to mention stock, local flora and fauna and entire wildlife ecosystems, bringing some to extinction levels.
<p>
The destruction doesn't end there. War and famine, drought, cyclones, hurricanes or typhoons, snow storms, heatwaves and the like.
<p>
All those situations can to greater or lesser degree benefit from amateur radio communications, either for amateurs affected, or for the community at large.
<p>
I started considering what would actually be required to be useful in such a situation. Could you be prepared for anything, or are you required to pick and choose? What does "being prepared" actually look like and what steps can you take once it's happening?
<p>
I asked myself if sending radio gear to amateurs who are affected by floods is the most effective way to actually help, or would it be better to pass the hat around and send the proceeds to their bank account?
<p>
Should you as an amateur drive into an emergency area and start communicating, or are there better ways to help?
<p>
There are local amateur radio emergency service groups under various names in different countries, some of which are highly effective, others much less so.
<p>
One attempt I made was to join the local volunteer state emergency services. For several reasons that didn't work out for me, but it remains a viable option for some.
<p>
Joining those types of groups gives you a framework, but does it actually answer the underlying question, that of effectiveness?
<p>
I have a drawer full of emergency service training manuals, each more dense than the next, but very little of it relates to the amateur radio. Many pages are dedicated to search and rescue, staying alert, first aid, keeping alive, hand signals, log books, mapping and the like.
<p>
I am left wondering why we as a community, with a proud century of activity, having one of the main principles as emergency communication appear to have such a poor track record of actually considering what dealing with an emergency looks like and what your own individual place could be in that situation.
<p>
We document our radios, antennas, power supplies, contacts, circuit board designs, contesting procedures and all the rest of it, but we don't seem to do the same for emergencies.
<p>
Why is that?
<p>
In my opinion, it's time to document emergency amateur radio and if you have already started, get in touch.
<p>
I'm Onno VK6FLAB
Listen:
Why do we communicate?
Foundations of Amateur Radio
<p>
The art of amateur radio is many things to many people. For me it's a technological challenge, a learning, a way to broaden my experience, a way to be technically active away from my consultancy. The place that amateur radio takes in your life might be the same, or it might be completely different, as varied as the people I've encountered since I became an amateur.
<p>
People from all walks of life with different experiences and vastly different stories. Truth be told, in the decade that I've been an amateur, I've spoken to and met people from more diverse backgrounds than in the forty years before that. I make that statement as a person who migrated across the globe twice, travelled through a dozen or so countries, stood on stage in front of thousands of people, taught countless classes and as a radio broadcaster interviewed people from all over the planet.
<p>
From paraplegic to quadriplegics, from people with terminal diseases to people struggling with their identity, from astronomers to astrologers, from train drivers to truck drivers, from mariners to motorcyclists, from working to retired, from healthy to hospitalised, from local to remote, from energetic to sedentary, from happy to sad, from connected to isolated and everything in between.
<p>
As a host of a weekly net for new and returning amateurs I've begun to notice that some people are falling away, either sitting on the side because they feel that they have nothing to contribute, or stopping communication altogether.
<p>
It occurred to me that for some people amateur radio is the only way that they connect to the world around them. It's the only way for them to meet people who are different, who walk a different path, who tell a different story. It's also sometimes the only thing that makes them get out of bed.
<p>
In a world where we're all busy, dealing with the realities of daily life, trying hard to figure out what our place is in that experience and trying hard not to lose your identity while you're attempting this, it's easy to overlook the amateur you didn't hear from for a week or a month.
<p>
I know that for several of my new friends, amateur radio kept them alive for longer and made them smile more often and made their life a little easier, even if several of them have become a Silent Key since I counted them as my friend.
<p>
When one of the main activities of our hobby is communication, it seems appropriate to take a moment to consider what that looks like from the other person's perspective. What might it be like to be acknowledged, to be validated as a human, to see them and their life, to speak with them, even if only briefly, and to take a moment out of our own busy existence and answer that CQ, or respond to a question, or smile with a fellow amateur.
<p>
There is another aspect to this, one which I've not actually seen in the amateur community. Perhaps I've been too busy to notice, but it appears that the venerable telephone circle, the idea that one person calls the next person on the list, who then calls the next and so-on. If the last person doesn't get a call within a set time, they call the list backwards and discover who is not answering their phone. It's an effective way for people to regularly talk to each other and it's an excellent way to make sure that everyone is OK.
<p>
In our own community of amateurs we can do the very same thing. Hosting a net is one way, having a daily commuter chat is another, but when you do this, take a moment to consider who didn't check in and see what they're up to.
<p>
It's fascinating to me that we're a hobby that's primarily made of old men, yet we haven't actually embraced our own ageing process as part of the experience. Sure there is a need to encourage new people into the hobby, but that's not the entire story. We should be so lucky as to speak with our friends on a regular basis, to check-in with each other and to make sure that we're all getting our daily dose of RF.
<p>
So, ask yourself how the community around you is doing and how you might take a moment to check-in with those not so near, but just as dear to you.
<p>
I'm Onno VK6FLAB
Listen:
Introduction to the terms of contesting
Foundations of Amateur Radio
<p>
One of my favourite activities is contesting. Essentially it's a time-limited activation of your station for the purposes of testing your skill and station against other participants. Contests are controlled by rules as varied as the amateur community itself.
<p>
That said, there are common terms and concepts and if you're not familiar with them, they can lead to confusion and disappointment when you inadvertently break a rule and see your hard work vanish into thin air.
<p>
I will note that what I'm discussing here is not universally true, so read the rules for each contest you participate in, something you should already be doing since rules are refined over time and it's rare to keep the same rules between years.
<p>
A contest starts and stops at a specific time, often expressed in UTC, or Universal Coordinated Time. You should know what your local timezone is in relation to UTC and take into account any variations like Summer and Winter time. Any contacts made outside these times don't count and you cannot log these against the contest.
<p>
Each contact or QSO is awarded a set number of points. It might be scored based on mode, band, power, time and sometimes distance. To encourage specific types of contacts, some might attract a score of zero. This does not mean that the contact is useless, which I'll get to shortly.
<p>
Your score is the sum of all the points you make for each contact. I will mention that contest logging software can track this to make your life easier, although it comes at the price of requiring a computer.
<p>
Sometimes a prohibited contact attracts penalties. Prohibited, as-in, by the rules of that contest. For example, some allow you to contact the same station more than once, others allow this only if you do it on a different band.
<p>
Speaking of bands. It's not permitted to make contest contacts on the WARC bands. In 1979, the World Administrative Radio Conference allocated the 30m, 17m and 12m bands for amateur use. These are not used for contesting. To avoid a contest, you can use those bands, but truth be told, you should try to use all the bands, even during contests, since it will help you operate your station in adverse conditions, something worth practising.
<p>
Many contests allocate additional scoring based on state, country, DXCC entity, CQ or ITU zone, prefix, or all of these together.
<p>
Both the CQ and ITU zones represent regions of the world. The CQ zones are managed by CQ Magazine and the ITU zones are managed by the International Telecommunications Union. A zone is represented by a number.
<p>
The DXCC is a system that tracks individual countries across the globe. If you make contact with 100 of these places, you've achieved your DX Century and you join the DX Century Club, or DXCC.
<p>
Consider a contact with me. You'd have a contact with VK6FLAB. It would also be a contact with the VK6 prefix, the VK DXCC entity, CQ zone 29 and ITU zone 58. If that's not enough, it would also be a contact with OC-001, the IOTA or Islands On The Air designation for Australia.
<p>
This is useful because for some contests these extra features represent points, often significant ones, generally referred to as a "multiplier".
<p>
To calculate your score, tally up all your contact points, then count all the features, CQ Zones, the ITU Zones, DXCC entities, states, countries, etc. and multiply your score with that count. If you contact 10 callsigns and get one point for each, you have 10 points. If in doing so you contact five contest features, you end up with an overall score of 50 points.
<p>
Often contests have different categories and rules for transmitter power level, the number of transmitters and the number of operators.
<p>
Definitions for these vary. High Power might be 400 Watts in Australia, but 1500 Watts in the United States. QRP or very low power might be 10 Watts in one contest, but 5 in another, so check.
<p>
Some contests have an assisted category where you're permitted to use tools like the DX Cluster where other stations alert you online to their presence on a particular frequency.
<p>
There is a concept of an overlay, where how long you've held your license, your age, working portable, battery operated, using a wire antenna or mobile, groups you with others doing the same thing. This means that you could be a rookie, youth, portable, battery, wire antenna, single assisted operator, all at the same time. It often pays to consider who else is in a particular group and make your claims accordingly.
<p>
If you're contesting with more than one person, a Multi station, there are rules for that too. Sometimes this includes the amount of land a contest station is permitted to use.
<p>
If you're a Multi-Single station, you might be permitted to use one transmitted signal on one band during any 10 minute period.
<p>
A Multi-Two might be permitted to use two simultaneous transmitted signals, but they must be on two different bands.
<p>
A Multi-Multi may activate all six contest bands at the same time, but only use one transmitter per band.
<p>
Some contests have a Short Wave Listener or SWL category, where you log all stations heard. There is also the concept of a check-log, where you log all your contacts, submit them, but don't enter the contest itself. You might have worked stations during the contest, but not according to the rules, because you might be aiming to get your DXCC. Submitting your log will help the contest organisers check other entries and validate the scores of the stations you contacted.
<p>
This might all be daunting, but if you read the rules of a contest and you're not sure, every contest manager I've ever spoken to is more than happy to help you understand what's allowed and what isn't.
<p>
One tip. Contesting is as much about the rules that are written as it is about the rules that are not. If you find a gap in the rules, and it doesn't go against the spirit of the contest, you're absolutely encouraged to use that to your advantage. If you do, you'll quickly discover why the rules change so often.
<p>
Preparation is everything!
<p>
I'm Onno VKFLAB
Listen:
It beeps!
Foundations of Amateur Radio
<p>
After weeks of attempting to get some noise, any noise out of my PlutoSDR I have finally cracked it. Not sure if cracked it refers to my sanity or the outcome, but beeping was heard from the Pluto on my radio, so I'm doing victory laps around the house, all conquering hero type affair, complete with whooping and hand waving.
<p>
In the end it all came down to serendipity and truth be told, I know it beeps, I've heard it beep, it does so on a predictable frequency, but why it exactly works is still a mystery that has yet to be discovered since the documentation I have isn't sharing and the example code I have contradicts what I'm seeing.
<p>
For context, a PlutoSDR, or Pluto, is a very capable software defined radio, perfect for experimentation. I've talked about it before in the context of using it as a receiver.
<p>
My most recent efforts involved coaxing my Pluto out of a corner after it sat there sulking for weeks. Turns out that not only was my USB power lead broken, which caused the blinken lights to stay off. When I finally figured that out, I discovered that one of the two wireless dongles I'd purchased together was Dead On Arrival. After a frustrating morning with the manufacturer who wouldn't take my word for it that swapping out the two identical units would not require installing the driver, something about Windows Device Manager on my Linux computer, I went back to the store who happily swapped out the faulty device on the spot. Mind you, the Pluto still isn't talking to my wireless network, but at least it's not the dongle anymore.
<p>
I plugged the Pluto into the back of my main workstation and discovered to my surprise that in addition to showing up as a thumb-drive, which I knew about, it also turned up as a network device, which I didn't know about.
<p>
It's been a while since I powered this up to play, so I updated the firmware which fixed some annoying issues and started to explore.
<p>
The aim of my quest was to create a proof of concept beep from the command-line on the Pluto.
<p>
If you're not familiar with this. The Pluto is running a flavour of Linux. You can connect to its command-line and run commands from inside the hardware.
<p>
This is important because for most radios, of both the analogue and software kind, you generate the information somewhere, like Morse Code, a WSPR signal, your voice, what-ever and then you send that to the radio. On an analogue radio it's likely to go across an audio cable of some sort and if you have a software defined radio, it's likely to travel from your computer across a USB or network cable to the radio to get processed.
<p>
This is different in that there is no such signal coming across the USB link. The link is used as a network cable to ssh into the radio where you can generate whatever you want. In my case Morse. If you're not familiar with ssh, think of it as a keyboard connection to a remote computer.
<p>
My script, hacked together as it is, more on that shortly, takes a string, like say "CQ DE VK6FLAB" and processes that character by character. It converts each into the equivalent Morse code dits and dahs and then uses those to turn on a test tone for an appropriate amount of time.
<p>
So, to send "CQ", the script changes that into -.-. --.- and then turns on the transmitter for three units, off for one, on for one, off for one, on for three, off for one, etc.
<p>
This is Morse code at its very simplest, the software equivalent of holding down a Morse key for the correct amount of time and then releasing it.
<p>
I disparagingly called it hacked together, because it's using the in-built busybox command shell that comes with the Pluto. If you're familiar, the actual shell is called ash, or Almquist shell. It's strictly limited in functionality, no arrays, minimal redirection, all very basic. Perfect for what I want to do, but not so much if you want to write software.
<p>
After working around the lack of arrays, one of the things that caused me the most problems was to discover just how to setup the Pluto to actually do this. I found a couple of examples online that pretended to work, claimed to be doing what they said they were, but nothing was heard on my local analogue radio. At one point I heard clicks, but no beeping.
<p>
After spending literally hours testing, scanning up and down the radio dial with my Yaesu FT-857d, I stumbled on a tone that stopped when my test script stopped. I started the script again and the tone came back. When it ended, the tone stopped again. I finally had a relationship between a tone on the PlutoSDR and the frequency on my radio.
<p>
So, with all manner of funky offsets in my code, subject to me understanding the how and what of them, I can now beep to my hearts content. Of course I've shared my efforts on github, cunningly called Pluto Beacon.
<p>
Have a look and tell me what I did wrong.
<p>
I'm Onno VK6FLAB
Listen:
What happens when you plug it in?
Foundations of Amateur Radio
<p>
The other day I took delivery of a shiny new circuit board populated with components and connectors. Knowing me, you'd assume that I'd been the recipient of some kind of software defined radio gadget and you'd be right.
<p>
One of the connectors was a micro USB socket, intended to be used to plug the hardware into a computer and to drive the circuit board.
<p>
The board came to me by way of a friend who saw it online, waxed lyrical about it and for less than $35, who could begrudge this exploration into a new toy?
<p>
Once it arrived, it sat on my shelf for a few weeks, enticingly packed in an anti-static bag, transparent enough to see the device inside, taunting me to open it up, plug it in and have some fun.
<p>
Today I opened it up and started researching my new gadget. It didn't come with any user manual, no URL, no model number, but it did have a callsign on it, so I started there. I'll note that I'm not going to repeat that callsign here for a number of reasons, which I'll get to.
<p>
My exploration discovered a site where this device was being sold. It also unearthed several international amateur radio forums describing what appeared to be this device, including circuit diagrams and specifications.
<p>
What I found harder to discover was software.
<p>
It appears that I have a clone of a device that may still be manufactured, or not, I cannot tell. I found some example code on github for the original hardware, but it seemed to require other libraries, but didn't actually specify those anywhere.
<p>
I opened up an online translation tool and started translating some of the wording on the circuit board in an attempt to discover just what information was written on the board.
<p>
The wording was clearly from a different culture, a different perspective and while it claims to come from a maker space that appears to promote women, it also contained a militaristic phrase which caused me to pause.
<p>
In that moment I came to a sudden and abrupt realisation.
<p>
How do I know what this piece of hardware actually does?
<p>
How do I know if when I plug it into the first available USB socket on my computer, it won't install anything nefarious, start connecting to the internet and start doing something unexpected? There's enough hardware on the circuit board to do that and even if the labels on the components tell me that they are a specific integrated circuit, how do I know that it actually is that chip?
<p>
The chips on this circuit appear to have a lot more connectivity than a simple receiver might warrant. One has 40 pins, the other 32. If the label is accurate, the data sheet for one of the chips indicates that it includes an 8-bit micro controller among its various functions.
<p>
I'll admit that I'm coming from an IT security background at this and you are free to argue that I'm being paranoid, but does that make me wrong?
<p>
I know that I don't know enough about this particular board or its origins that for now it's going to remain inside its anti-static bag, taunting me with the possibilities of the connectors it offers, but until I know more about the provenance of this gadget, it's going nowhere near any of my computers.
<p>
If you have suggestions on how to proceed, don't be shy. I did briefly consider plugging it into a Pi, but how would I know if it updated the firmware, forever compromising that Pi?
<p>
Don't get me wrong, I'm not saying that this board does any of this. My point is around discovering if it does, or not, one way or another.
<p>
No doubt some might think I'm overly suspicious and there is truth in that, but in my profession it pays to be vigilant. The underlying issue is that of validation. There's anti-virus software available to deal with malicious code, but how do you do such a thing for malicious hardware?
<p>
Again, I'm not saying that this circuit board is doing anything other than being a USB connected receiver, but how would you know? How would you verify that? And how do we in the amateur community weed out the nefarious tools from the legitimate ones?
<p>
I'll leave you with one thought. When was the last time you plugged your phone into a free charger on the bus or at the airport? How do you know that your phone wasn't hacked?
<p>
I'm Onno VK6FLAB
Listen:
How to compare radios
Foundations of Amateur Radio
<p>
One of the topics I've been talking about lately is the idea that we might be able to measure the performance of your radio in some meaningful way using equipment that can be either obtained by any amateur, or by introducing a process that allows results to be compared, even if they have been generated differently.
<p>
Recently I came up with a tool that automatically generates a spectrogram of an audio recording. That on its own isn't particularly interesting, but it's step one in the processing of an audio signal. In addition to the spectrogram, I also created a tool that generates a tone frequency sweep, think of it as a tone that changes frequency over time, let's call it a sweep.
<p>
If you combine the two, you can generate a spectrogram of the sweep to give you a starting point or baseline for comparison. You can build on that by using your radio to transmit that sweep and record the result using a receiver. In my initial experiments, I used an RTLSDR dongle to receive the audio with some success and a boatload of spectacular harmonics, but I wanted to find a better, more accessible way to do this and during the week I realised that my Yaesu FT-857d that's sitting in my shack, is connected to a perfectly functional antenna and with a few settings it could do the job perfectly.
<p>
One of the biggest issues with my RTLSDR setup was squelch. That is the difference between what is a legitimate transmission and what is noise. Set it too high and you hear nothing, set it too low and you hear everything, including background noise.
<p>
Since the VHF or 2m noise levels are quite high at my location, or QTH, I normally have the squelch completely closed. This is fine if you're normally using a strong repeater, but if you're attempting to receive a weak hand-held, that's never going to work.
<p>
As any self-respecting amateur I was dragged down the path of last resort to read my user manual where I discovered that in addition to CTCSS, a way to transmit a tone to open a repeater, there's also a setting called Tone Squelch or on my radio TSQ, which will keep my radio squelch closed, unless it hears the CTCSS tone from another radio.
<p>
Truth be told, I had to read a different user manual to discover how to actually set the CTCSS tone on my handheld to test, but that's just adding insult to injury. It has been a while since I read any manual, even though I try to get to it once a year or so. I blame it on the lack of field-day camping. That's my story and I'm sticking to it.
<p>
So, combining all this, the spectrogram generator, the sweep, CTCSS, and adding a Raspberry Pi with some website magic, if you're interested, an AWS S3 bucket, I now have a service that listens on a local frequency, opens the squelch if it hears the correct CTCSS tone, records the incoming signal until it stops, then generates a spectrogram from that audio and uploads it to a web site.
<p>
None of this is particularly complicated, though I did have some bugs to work through. I've published the code as a branch to my existing frequency-response project on github and I've asked my local community to experiment with what I have on-air before I start doing more far reaching experiments.
<p>
For example.
<p>
If I were to tune my radio to a local repeater output frequency, rather than the simplex one I'm currently on, I'd be able to record and generate spectrograms for each transmission coming from that repeater. If that repeater was connected to the internet, using AllStar, IRLP, Echolink, DMR or Brandmeister, or even all of them, the global community could send their audio to my recorder and it could generate a spectrogram on the spot.
<p>
If using that repeater, you played a sweep into your microphone, or used your digital audio interface to play the sound, you could then compare your signal path against others and against the baseline response.
<p>
One of the issues with doing this is that much of the audio that travels across the internet is pretty munched, that is, it's compressed, frequencies are cut-off, there's all manner of interesting harmonics and the value of the comparison appears limited at best.
<p>
Once I have my multi-band HF antenna, which I'm told is still being built, I intend to set this contraption up on HF where we can do point-to-point recordings and we end up having a direct comparison between two stations who transmit into my frequency-response software.
<p>
I should add some disclaimers here too. At the moment I'm only using FM. The intent is to get this to a point where I can compare any mode, but when I move to HF, I'll likely start with Single Side Band and go on from there.
<p>
One other annoyance is that any user needs to configure CTCSS to make this work, which is yet another hurdle to overcome, not insurmountable, but I like to keep things simple when you're starting to learn.
<p>
Also, the harmonics still show, even on an analogue radio, so there's plenty more to discover.
<p>
In the meantime, what kinds of things can you think of to use this for?
<p>
I'm Onno VK6FLAB
Listen:
Pictures can say more than words
Foundations of Amateur Radio
<p>
Recently I've spoken about measuring the frequency response of your radio and what the benefits of doing so might be. Today I've got some progress to report and some initial discoveries. Again, this is preliminary, but then all of this hobby is experimentation, so that should come as no surprise.
<p>
Let's start with the mechanics of what I'm doing and a "duh" moment I need to confess.
<p>
The aim of this process is to transmit a known audio signal, receive it, record it and create a spectrogram from it. This allows us to compare the original spectrogram against the received one and show just how the audio path has been affected by getting the audio into the transmitter, the processing by the transmitter, the propagation between the transmitter and receiver, the artefacts introduced in the receiver and any recording device.
<p>
To begin this process I started off with an audio file of my voice. That wasn't very helpful, since it's a complex signal and comparing my voice before and after is a non-trivial process. At some point I intend to come back to voice before and after comparison, but that's on the shelf for now.
<p>
The audio that I'm using is a frequency sweep, lasting 5 seconds. That is, there's a tone that changes frequency from DC to 5 kHz. When I looked at the spectrogram of that, it shows as a curve with time against frequency. It occurred to me that I could make two of those sweeps at the same time to measure distortion, so I added a reverse frequency sweep from 5 kHz down to DC. Now I've got two crossing lines showing in my spectrogram.
<p>
To transmit this audio, I'm using the same tool I use to automatically call CQ during a contest. Every so many seconds I transmit this audio into a dummy load and at this point I should mention that my "duh" moment was that I was attempting to transmit into an antenna and record from a dummy load, rather than transmit into a dummy load and record from an antenna. I still cannot believe that I did that.
<p>
Moving on.
<p>
The recording is done using an RTLSDR dongle. In the current initial version I'm using a tool called rtl_fm to tune the dongle to the same frequency as my transmitter. I send the audio from there to the same tool I used to generate the original audio, SoX, that's Sierra, Oscar, X-Ray, and have it detect the silence between each transmission and record each into a new file. If I leave it running, every time I transmit something, SoX will create a new audio file.
<p>
I'm saying that quite quickly, but getting the squelch and silence detection working in my noisy environment took most of a day and it's specific to my station, today. I'll have to figure out how to make this smarter, but for now I have some data.
<p>
A spectrogram is generated for each audio file and then we can compare pictures. What was sent, audio wise, and what was received, audio wise. To be clear, I'm not sending images, I'm sending audio and comparing the spectrograms of this audio.
<p>
I will also note that I'm currently using FM as the mode. I intended to do this with SSB, but the amount of effort to get the squelch right has left me with a future project to achieve that.
<p>
The code itself is pretty rudimentary, but I've uploaded it to my github page. I've also added the pictures to my project website, which you can find at vk6flab.com.
<p>
One initial observation, one that I don't yet understand, is that what I sent and what I received don't look the same. My pretty curves in the original audio come back with spectacular harmonics all over the place, very pretty to be sure, but not quite what I was expecting, let's call it an educational challenge.
<p>
Before I forget, just because I'm using a Yaesu FT-857d, a Raspberry Pi, an RTLSDR dongle, an antenna and a dummy load, doesn't mean that you need to. Essentially, what this does is generate a special audio file, transmit it, receive it, record it and generate a spectrogram. You can play the audio from your own computer if you have digital modes set-up, or from your mobile phone if not.
<p>
Recording can be something sophisticated with off-air monitoring, or it can be a recorder held in front of your receiver.
<p>
One final note. You can change settings on both the transmitter and the receiver to see what they do in relation to the audio, so experiment.
<p>
I'm Onno VK6FLAB
Listen:
Testing your radio's audio frequency response
Foundations of Amateur Radio
<p>
During the week I was reading a comment from another amateur about digital modes. Tucked inside that comment was a phrase that could easily have been overlooked, but it reminded me that there is plenty to learn and test in the field of amateur radio.
<p>
The phrase, "requires actual understanding of audio level paths" was uttered by Chris, VK2CJB and it prompted a brief conversation at the time, but I've been working on it ever since.
<p>
Where I arrived at is an attempt, incomplete as yet, to design a mechanism to show the impact of various transmitter settings on the received audio in such a way that you can test your own gear and see the result.
<p>
Before I explain how I'm doing this, let me describe why it's important.
<p>
Using a radio in concept is pretty simple, if you yell into the microphone, the audio comes out distorted and if you whisper, it might also be distorted, but in a different way, neither is conducive to communication.
<p>
One way to improve this is a tool called the ALC. Using Automatic Level Control as a guide to what level your audio should be is outlined in every amateur radio manual I've seen, but how much it matters and to what extent is left unsaid. If you apply a filter or any number of other fancy options, what happens to your audio?
<p>
To get some sense of what I'm describing, listening back to your own voice after it comes across HF SSB is surprisingly distorted in comparison to a local recording.
<p>
You might argue, what's the harm, as long as the other station can hear my voice, we're good to go.
<p>
Sure, if voice is all you're using, but what if it's data? In that case, the audio you're transmitting is actually encoded digital information. To decode it, the software needs to deal with frequencies, distortion and levels to name a few.
<p>
In computer science, "garbage in, garbage out" is the concept that flawed, or nonsense input data produces nonsense output. In our case, if you transmit garbage, the receiver is going to start with garbage and what gets decoded is likely not what you expect.
<p>
Without going into error correction, essentially, the cleaner the path between the transmitter and the receiver, the higher the chances of success and to be fair, you already know this when you attempt to work a pile-up on a noisy band. "Again, again, just the prefix, again!", sound familiar?
<p>
To achieve this I started with the idea that you could transmit a tone and if you knew what it was, you could determine the difference between what was sent and what was received.
<p>
My first step was to generate a single 1 kHz tone, but then I wondered what would happen if you did multiple tones, one after the other. My current version is an audio frequency sweep, running from 0 to 5 kHz in five seconds. It's essentially a computer generated sequence of tones with known characteristics. You transmit this audio file using your radio and then record it off air, either from a local receiver, WebSDR, or the radio belonging to a friend.
<p>
Using the recording, you can create a spectrogram, a picture, showing the frequencies over time present in the audio. Compare the two and you just learnt what each setting on your radio does precisely to the audio.
<p>
Of course it's simple for me to say this, but I'm working on using a tool I've spoken about before, csdr, to do the heavy lifting, so you can actually do a meaningful comparison between the various audio files.
<p>
In the mean time, I've managed to use SoX, the so-called Swiss Army knife of sound processing programs to both generate the audio sweep and draw a preliminary spectrogram.
<p>
Next up is showing some side-by-side images of various radio settings and their effect on the spectrogram. I'll publish this on my website when I have something to show-and-tell.
<p>
I also don't yet know if my source audio file is going to be sufficient, but I'll subject that to some testing as well. For example, I'm investigating multiple simultaneous audio sweeps with different frequency ranges. The more complex the spectrogram, the more we might be able to learn from the distortion on receive, but time will tell.
<p>
If you have some ideas on how to improve this, let me know.
<p>
I'm Onno VK6FLAB
Listen:
What's in a Dream?
Foundations of Amateur Radio
<p>
On the 6th of June, 2004, two Brazilian amateurs Roland, PY4ZBZ and Arnaldo, PY4BL made a historic contact on 40m. The distance was not particularly significant, only 70 km, but the mode was.
<p>
Using 2.1 kHz bandwidth, so it could fit within an amateur radio SSB transmission, they used software created by Swiss amateur Francesco, HB9TLK to make the very first HamDream exchange.
<p>
This technological advancement represents the birth of what we now call HamDRM and Digital SSTV and how it came about is an adventure that needs documenting, since what we have is written in a combination of Portuguese, German and English, cobbled together from broken websites, archives, source code, commit comments and lost links.
<p>
To provide some context, there is a broadcast radio mode called DRM, or Digital Radio Mondiale. At this point I should mention that this has absolutely nothing to do with Digital Rights Management with the catchy acronym of, you guessed it, DRM. As you might expect, this acronym clash is unhelpful, to say the least, when you're trying to find information about this radio mode.
<p>
Digital Radio Mondiale, or DRM, essentially defines a digital standard for radio broadcast transmissions. It can handle multiple audio streams as well as file exchange and is used by broadcasters across the globe. Mondiale, in case you're curious means worldwide in French, seems my high school language lessons have finally been put to good use, my French teacher in the Netherlands will be thrilled.
<p>
DRM is more efficient than AM and FM and as an open standard, it's gaining popularity. The first broadcast using this mode took place on the 16th of June 2003, during the World Radiocommunication Conference in Geneva.
<p>
An open source implementation of this mode is called Dream. The source code is available online and is capable of being compiled for Windows, MacOS and Linux. Dream was originally written by Volker Fischer and Alexander Kurpiers. The Dream project started in June of 2001 and today it has many contributors.
<p>
The DRM standard uses different bandwidths depending on which mode is used. The narrowest DRM mode uses 4.5 kHz, but modes using 100 kHz exist. By comparison, a typical analogue amateur radio uses 2.7 kHz for SSB. Using the source of Dream, Francesco built a modified version, called it HamDream and let it loose on the world. It was used for that very first 70 km contact between Roland and Arnaldo.
<p>
Several versions of HamDream existed. The first QSO used 2.1 kHz and the last version of HamDream used 2.5 kHz bandwidth. To fit digital audio inside that narrow bandwidth it used different audio compression techniques, called a CODEC, namely LPC10 and SPEEX.
<p>
According to Francesco, HamDream is the basis for all current amateur radio 2.5 kHz HamDRM programs. He goes on to say that it's outdated and the source and executables were removed from the net. Personally I think that's a shame, since it represents part of the history of our community and I think that putting the source online in a place like GitHub would be beneficial to the hobby.
<p>
The 2.5 kHz HamDRM mode is implemented in several places. QSSTV, EasyPal and WinDRM to name a few. No doubt it's elsewhere. Of those three, only QSSTV survives. The source code for EasyPal, written by Erik VK4AES, now SK, was lost, apparently when the computer on which it lived was sold by his estate. Ironic really, since EasyPal was written because Erik lost a previous application due to a lightning strike nearby and was forced to write a new application from scratch.
<p>
WinDRM appears even more elusive. There's a repository on the now archived Google Code site. There are derivatives that appear to use a version of WinDRM, but details are hard to find. An archive I have shows a commit by Francesco, HB9TLK from 2008. I've yet to learn how this relates to the overall picture.
<p>
In parallel, in 2005, a few enterprising students made a MATLAB implementation of DRM. Called Diorama and written by Andreas Dittrich and Torsten Schorr it forms the basis of a Linux open source HamDRM receiver written by Ties, PA0MBO, chosen because it had a better performance in marginal conditions than Dream did. It's called RXAMADRM. Ties also wrote an open source transmitter, cunningly called TXAMADRM. It was based on the source code of Dream, specifically v1.12b.
<p>
If at this point your head is exploding, I wouldn't blame you.
<p>
Let's recap.
<p>
There's an open broadcast standard called DRM. An open source, cross platform tool called Dream, in active development, implements that standard.
<p>
A special, now discontinued, version of Dream was created called HamDream. It used less bandwidth than DRM and forms the basis of a standard that we now call HamDRM, which underpins Digital SSTV.
<p>
HamDream forms the basis of the discontinued products, EasyPal and WinDRM, and lives on in TRXAMADRM and QSSTV, both Linux open source.
<p>
In amateur radio terms HamDRM is one of the ways we can efficiently exchange digital information across long distances.
<p>
At this point you might wonder why it matters?
<p>
For starters, this is part of our history of amateur radio. The HamDRM mode is poorly documented, if at all. It forms the basis of several modes in use today and writing your own software is made all the more challenging because much of the design and development of this mode has been lost.
<p>
What's more, HamDRM is an example of "modern radio". It uses the same fundamental techniques used by the 4G and 5G mobile phone network, as well as modern Wi-Fi. Losing this is a massive step backwards for amateur radio.
<p>
This article alone represents a week of research by two people, thank you Randall VK6WR, and I won't be surprised to learn that it contains errors and omissions. It shouldn't have to be this hard to discover how a mode works, what is used to make it tick and how to write new software to implement a new application.
<p>
Gotta love open source. Speaking of which. If you have source code copies of HamDream or WinDRM, I'd love to hear from you. cq@vk6flab.com is my address. If you have documentation on the design of the HamDRM mode, I'll owe you a beer, or a glass of milk, your choice.
<p>
I'm Onno VK6FLAB
Listen:
Bringing an upconverter into your life
Foundations of Amateur Radio
<p>
A couple of days ago, after months of anticipation, an unassuming little box arrived on my doorstep. Inside the box was a nondescript electronic device with two SMA connectors and a USB socket. Other than the branding, there were no markings on the device and it came without any instructions.
<p>
It did come with a couple of SMA adaptors, which came in handy.
<p>
A little research later determined which of the two SMA adaptors connected to an antenna and which connected to a radio.
<p>
The gadget itself is called an upconverter.
<p>
It's an interesting little device that essentially mixes two frequencies together, creating two new ones, start with say 720 kHz and mix it with 120 MHz and you end up with 120.720 MHz and 119.28 MHz. In other words, if you mix two frequencies together, you end up with both the sum and the difference of those frequencies.
<p>
If you have a radio that can listen to 120 MHz, but cannot listen to 720 kHz, then using an upconverter, you can, as it were, expand the frequency range of your radio to hear different signals.
<p>
I purchased the upconverter with the intent of connecting it to my PlutoSDR, since the lowest frequency it can do is 70 MHz. Combine the two and I should be able to listen to all of the amateur HF frequencies at once.
<p>
Given that my PlutoSDR is currently doing something else, I had a look at using the upconverter with my WSPR beacon monitor that uses an RTL-SDR dongle. Technically it's not required, since my particular dongle can be used to tune to HF frequencies, but as an experiment, it works well enough.
<p>
So, I connected the antenna to the upconverter, the upconverter to the dongle and the dongle to a Raspberry Pi, a single board computer that runs Linux. Essentially the exact same setup I've been running for years, except that I inserted the upconverter between the dongle and the antenna.
<p>
That and some power took care of the hardware.
<p>
The software initially gave me some challenges. After discovering that the tool I'm using, rtlsdr_wsprd, has an option for an upconverter, I was up and running in minutes.
<p>
So, at the moment, and for the next foreseeable little while, my WSPR monitor is using an upconverter to scan HF. Technically this should increase the sensitivity by a significant amount, since the dongle is better suited to tuning to higher frequencies than it is to lower ones, but only time will tell.
<p>
I updated my monitoring scripts to take into account if the frequency I was monitoring was out of range, so it currently won't report on anything above 60 MHz, but then that's fine for what I'm working on.
<p>
I've updated the script on github if you want to have a look. It's nothing fancy, it essentially checks to see if there's a file called upconverter and if so, it calls a slightly different monitoring script.
<p>
Given that I have existing logging data associated with this monitor, I should be able to discover if there's any significant difference between what I've been monitoring to date and what's coming in now that an upconverter is in the listening chain. Theoretically, I should be able to hear weaker signals, but time will tell.
<p>
One thing that was interesting whilst I was discovering how this all works and hangs together is that it wasn't immediately obvious how to set it all up in software. I tried several tools to make sense of the data. In the end the combination of gqrx, setting the local oscillator offset to a negative frequency, in my case 120 MHz, got me to the point where I could set the frequency to 720 kHz and hear my local broadcast station, whilst the software actually, secretly behind the scenes, added 120 MHz to that and tuned the radio to 120.720 MHz.
<p>
Once I got my head around that, things started falling into place.
<p>
The same is true for rtlsdr_wsprd, adding the upconverter flag with the value of 120MHz, got my monitoring station up and running.
<p>
This is a pretty user friendly way of getting started with frequency mixers. You might recall my exploration into components apparently made from unobtainium. The intent is to use a variable frequency to achieve a similar thing, but that's a project still on the drawing board, for now, I have a fixed frequency, 120 MHz, which is plenty to get started.
<p>
If you're curious why I'd want a stable variable frequency, consider for example, what might happen if you transmit from a HF frequency into an upconverter. Perhaps you could use your HF capable WSPR beacon to make a signal on 2m or 70cm. 120 MHz won't cut it, but perhaps you can work out what's needed to get from the 10m WSPR band to the 2m WSPR band, or the 70cm WSPR band.
<p>
I'm Onno VK6FLAB
Listen:
When I said Parrot Repeater ... I likely had a different picture in mind.
Foundations of Amateur Radio
<p>
A little while ago I mentioned in passing that I was considering implementing a parrot repeater to help determine how your radio is performing. Discussion afterwards revealed that not everyone had the same picture in mind, so I thought I'd share with you some of what I'm considering and why.
<p>
Most of the modern radio landscape revolves around hooking a computer up to some type of radio frequency capable device. Commonly it's the audio and control signals that travel between computer and radio, but there are plenty of examples where raw data makes the journey, like in the case of an RTL-SDR dongle.
<p>
That journey is increasingly made using USB, the cable, not the sideband, and limits are based around the maximum speed that a Universal Serial Bus has. Essentially the amount of data that you can process is limited by how fast your computer can talk to the radio.
<p>
For my parrot repeater, I'm imagining a device that can receive RF from any radio and process that signal to determine what the centre frequency is, the deviation, stability, the mode, what ever parameters I end up being able to determine, a whole other discussion on its own. In response, the idea is that the device generates a report and either presents that using text to speech, or as a web-page, or both.
<p>
Using traditional methods, this would involve a radio, a computer, some software, connections between the radio and the computer, not to mention power for both the computer and the radio, an antenna and perhaps an amplifier. The picture I have in mind is not anything like that. I'm imagining a single device that takes power and does all I've described inside the one device. No external computer, no audio cables, no control cables, no hard drives, not anything, just a PlutoSDR and a power source connected to an antenna or two.
<p>
You might think that's fanciful. As it happens, we already have some of that today. When I run dump1090 on my PlutoSDR, it presents itself to the world as a website that I can visit to see which aeroplanes are within range, where they are exactly on a map, what messages they're sending and where they're going. All of the processing is done inside the PlutoSDR. All I have to do is give it power and an internet connection.
<p>
This is possible because the PlutoSDR is essentially a computer with RF. It runs Linux and you can write software for it. Unlike my Yaesu FT-857d, which also has a computer on board, rudimentary to be sure, but a computer none the less, it cannot be altered. I cannot load my own piece of software, launch a web browser and point it at my Yaesu, not without connecting an external computer that in turn needs to be connected to the radio. I might add, that this is is how many repeaters work and how devices that implement AllStar and Echolink manage to make the jump between the Internet and the world of RF.
<p>
If your eyes are not lighting up right now, let me see if I can put it in different terms.
<p>
The PlutoSDR has the ability to access signals between 70 MHz and 6 GHz. It can do so in chunks of 56 MHz. Said differently, if you were able to consider all of the amateur HF spectrum, from zero to 54 MHz, you could fit all of it inside one chunk of 56 MHz that the PlutoSDR is capable of. You couldn't send it anywhere, since you're limited to how fast a USB cable is, but you could technically process that inside the PlutoSDR itself.
<p>
To get the PlutoSDR to see the amateur HF bands you could connect it to a transverter, in much the same way that today many 2m handheld radio owners use a transverter to get to 23cm, except in this case, we're going the other way.
<p>
In order to actually use this massive amount of information, you're going to need to do some serious signal processing. Accessing 56 MHz of raw data is hard work, even if you don't have to get it across a serial connection. As it happens, the PlutoSDR also comes with an FPGA. As I've mentioned previously, it's like having a programmable circuit board, which can be programmed to do that signal processing for you. It has the capability to massage that massive chunk of data into something more reasonable. For example, you might be able to use it to extract each of the amateur bands individually and represent them as an image that you might show to the world as a waterfall on a web browser.
<p>
Now to be clear, I'm not saying that any of this exists just yet, or fits within the existing hardware constraints. I'm only starting on this journey. I'll be learning much along the way. No doubt I'll be using existing examples, tweaking them to the point that I understand what they do and how they work. I've already been talking about some of this for years. As you might have discovered, this adventure is long with many different side quests and at the rate I'm going I'm confident that this represents the breadth and depth of what amateur radio means to me.
<p>
So, if you're wondering why I'm excited, it's because the amateur radio world of opportunity is getting bigger, not smaller.
<p>
I'm Onno VK6FLAB
Listen:
Products made from unobtainium
Foundations of Amateur Radio
<p>
The other day I received an email from a fellow amateur, Elwood WB0OEW. We've been exchanging email for a little while and having been in the hobby since before I learnt to ride a bicycle, he's always got some interesting insight into something I've said and an encouraging word to share.
<p>
This time he introduced me to a project he built and published a couple of years ago. It's a variable frequency standard, built from parts and, at the time, costing all of about $150, more on that shortly. Compared to the microwave oven sized HP-606A signal generator sitting on my bench in bits, with some diligent layout, this project could fit inside one of the valves that drives that massive hunk of equipment.
<p>
As an aside, truth be told, I'm a little afraid of the HP. It managed to pop the RCD, a residual current device, or safety switch, in my house and in doing so, took out the UPS that powers my main workstation, so, not unexpectedly, I'm reluctant to repeat the experience. Once I understand precisely what happened, I'll pick up the restoration efforts and based on what I learnt today, it might get me where I want to go faster.
<p>
Elwood's frequency standard is a very interesting project that delivers a very precise Variable Frequency Oscillator or VFO with an accuracy approaching 1 part per billion. His project uses an Arduino to control a touch sensitive display, read a knob and set and correct the frequency using a GPS as an accurate external time source. It's all very compact, easy to follow and I immediately thought that this would be an excellent project to build with a little twist.
<p>
I'm thinking that it would be really great to have this device sit on your local network and make it remote controllable.
<p>
The heart of this frequency standard project is a chip called an Si5351. The Silicon Labs Si5351, to use its full name, was first sold by Mouser in 2010 and has been popular since. You'll find it in all manner of places, including the Linux kernel source tree, the QRPlabs QCX and BITX to name two, the Elecraft KX2, scores of Arduino projects and countless frequency source products and projects used in amateur radio.
<p>
The Si5351 is a configurable clock generator. Think of it as a programmable crystal that can be configured on the fly, as often as you like. For configuration, it uses an I2C bus, or Inter-Integrated Circuit communications protocol, a special serial bus intended for chip to chip communications, invented by Philips Semiconductors in 1982. That's the same Philips from the light bulbs and audio cassettes, CD, DVD and Blu-ray, also the Philishave. To complete the picture, Philips Semiconductors became NXP in September 2006.
<p>
Back to our frequency standard project.
<p>
I wondered if I could cut out the Arduino from the actual correction process, since I didn't need a display or a knob and discovered that the Si5351 comes in several flavours. Elwood's design uses the A-version, but there's also a C-version that has the ability to take in an external clock, like say that from a GPS, and correct within the chip itself.
<p>
With that information in hand, I figured that I could use a simple Wi-Fi capable system on a chip, something like say an ESP8266, to configure the clock and take care of communications with the outside world. In the process I'd learn how to do a bunch of new things, including my first foray into generating RF, first time writing actual firmware, first time designing circuits and no double many more firsts.
<p>
Then I hit a snag.
<p>
It seems that the Si5351 has gone from commonplace to zero in stock. Not just zero in stock in Australia, or the US, no, zero in stock anywhere. There are a few A-version breakout boards, that is, the chip on a circuit board, available from one supplier. There is also a new compatible chip, an MS5351M, available from China, but that's a drop-in for the A-version, not the C-version.
<p>
So, where it stands is that I can almost taste the design, essentially three chips, an almost trivial circuit board, some SMA connectors, a power source and an external GPS antenna, something that would represent the very first circuit I actually designed, which is a long way from reading the circuit diagram for my Commodore VIC-20 back in the days before I owned a soldering iron.
<p>
It did bring me face to face with an odd realisation.
<p>
There are components that we use in day-to-day use, ones that are common, used across many different industries, that come from a single source. I should also mention that this particular manufacturer just got sold to another company, which doesn't help matters.
<p>
Nobody seems to know how long this shortage might last with forecasts varying wildly, but I'm beginning to wonder how many of these kinds of components exist and how we might reduce our dependence on single supplier hardware.
<p>
I'm also starting to look at using an FPGA to do all of this in software, but that's going to take some time, of course we could start using valves again. My 1960's era HP signal generator is starting to look much less intimidating.
<p>
I'm Onno VK6FLAB
Listen:
Leaving the hobby ...
Foundations of Amateur Radio
<p>
The other day I came across a how to video on becoming a radio amateur. It's a recurring kind of publication, the kind that I've contributed to in the past.
<p>
I wondered what it would take to leave the hobby.
<p>
First of all, I'd have to let my callsign lapse. That's easy enough, but I paid for five years, so it's going to take a while. When it has finally ceased being mine, have I stopped being an amateur?
<p>
For one, my qualifications would still be in the regulator's database, likely well beyond my breathing years. I wonder if they implement the right to be forgotten?
<p>
Another thing I'd have to do is stop knowing about how antennas work in day-to-day situations. I'd have to stop noticing the location of free to air television antennas, mobile phone towers, Wi-Fi antennas throughout the community and even the network in my home.
<p>
I'd also have to say goodbye to all the friends I've made around the place. There's hundreds of people scattered around the globe who with a single word might lure me back into their world, and with that the risk of being sucked back into the community once again.
<p>
At a minimum I'd have to stop using computers, or radios, or electronics really. I'd have to stop wanting gadgets and measuring equipment, not to mention having to mothball my soldering irons and give away all my heat shrink.
<p>
I'd have to give back the space I've eked out in the house and return it to the general living space it once was. I'd also have to sell all my radio gear and antennas. I'd have to rip out the coax, fix up any holes, cancel pending orders for new antennas and donate my books and magazines to the local library.
<p>
I'd have to stop looking at electronics magazines, cut up my loyalty cards for the local electronics and hardware stores and start an online store to sell all the connectors and adaptors I've amassed over the time I've been part of the community.
<p>
I'd have to forget the phonetic alphabet that I use almost daily and start using crazy words to spell things over the phone like a normal person does.
<p>
Experimentation would be a thing of the past and would be frowned upon as a fringe activity, one only suited to madmen and amateurs, and I'd have to stop investing my time in software and projects that might one day be used in amateur radio.
<p>
One of the hardest things to give away would be my curiosity, the one thing that's innate to my wellness. I'd have to stop asking Why? and How? all the time. I'd have to plead ignorance when someone asks how coax works and what's inside a blob of goop on a random circuit board they found on the side of the road.
<p>
Then there's the other things like physics and general science. I'd have to disavow all knowledge of these activities. I'd have to stop looking at the stars and stop wondering which radio frequencies were being emitted from all over the night sky.
<p>
I'd have to become ignorant of emergency services and communication, of event management and club life. I'd have to feign interest in anything that wasn't science or technology and I'd have to keep a straight face and my mouth shut when someone extolled the virtues of an irrational belief system.
<p>
I would likely have to give up my job as an IT consultant and start on a more manual job. Perhaps I'd take up gardening, though I'm not sure how I'd do in the weather at my age.
<p>
Even if I achieved all that, and kept it up for the rest of my life, I'd still be an amateur, just one hiding from the hordes of humanity striving to live on this ball of dirt, hurtling through the heavens on a journey through the stars.
<p>
I'm not sure I could do that.
<p>
So, for better or worse, as I see it, once an amateur, always an amateur and if you're curious and believe in science and technology, I'm here to say that you're well over halfway towards being an amateur! Welcome to the club!
<p>
I'm Onno VK6FLAB
Listen:
What testing equipment is essential?
Foundations of Amateur Radio
<p>
After discussing the notion that it's not really possible to determine how your gear is performing without measuring, several people commented that in the good old days an amateur was expected to have sufficient equipment to test performance of their gear.
<p>
I flippantly pointed out that once upon a time, computers ran on punch cards too. That's not to dismiss the notion of testing, but rather that times have changed. Testing equipment that was suitable in the 1980's is still available around the place, but expect to pay for it. Some of it is still relevant, some less so.
<p>
Even if you do acquire suitable equipment, how do you know if what you're measuring is real? How do you know if the frequency counter that you have is accurate, how do you know if 1 Volt is 1 Volt, or 1 second is 1 second? As I've said before, measurement is the act of comparing two things.
<p>
If you think that's ludicrous, consider the rulers and tape measures in your home. They all indicate the same measurement, right? Just for a laugh, pull out all the ones you can find and see what you discover. If you've not done this, you're in for a surprise.
<p>
I don't want to dissuade you from getting testing equipment, far from it, but don't expect to fork out to get the equipment and call the job done. The point being that spending lots of money on gear isn't the end of the story, it's just the beginning and in my opinion it's not the place you should start.
<p>
Based on community responses, ninety recommendations in all, so hardly scientific or representative, but still a good feel for the space we're playing in, the single most important piece of equipment you should get after sorting out your radio, antenna, coax, power supply, computer, software and other fun things we fill our shacks with is the Digital Multi Meter. You can spend anywhere from $10 to $500 on one, but it should be high on your list. As with the rulers, your results will vary, so be mindful of that when you go shopping.
<p>
While the SWR meter and the Watt or Power meter appear regularly, they're not the next highest ranked testing gear. Mind you, most current radios have those built-in to some extent, so perhaps the numbers are somewhat distorted here.
<p>
The next essential piece of equipment is some form of monitoring. Either active, passive, programmable, automated, manual, what ever. Hardware like the NanoVNA, the TinySA, even using a Software Defined Radio feature high on the list. Most of these devices either generate a signal to test against, or they rely on your radio to do the heavy lifting, depending entirely on what you're testing. An antenna analyser is among these kinds of tools.
<p>
As an aside, the dummy load, either a high power one, or a more modest one, come recommended by many different people.
<p>
Together with this list of monitoring equipment comes associated accessories, adaptors, patch leads, attenuators and filters.
<p>
After that comes equipment such as variable power supplies, Watt meters, grid dip meters, oscilloscopes and frequency counters.
<p>
I will observe that from the responses I received there was a distinct flavour to the recommendations.
<p>
On the one hand there was the combination of recommending something like a station monitor, or a signal generator, an oscilloscope and a frequency counter, including things like a Bird 43 RF Watt meter. On the other hand were recommendations for spectrum analysers, NanoVNAs, SDRs and the like. It's not quite across the analogue to digital divide, but it's close.
<p>
Note at this point that I'm a software guy in the process of restoring an analogue HP 606A Signal Generator from the early 1960's, so I'm not pointing the finger anywhere.
<p>
There were other tools recommended too, an LCR meter, a tool that allows you to measure Inductance, Capacitance and Resistance, something you can buy in kit form if you want to get started, or similarly, can be purchased for varying amounts of money online. Speaking of money, varying amounts that is, the service monitor was on the wish list for several people. Prices between that of a new radio or a new car with varying amounts of warranty.
<p>
I will make mention of a bi-directional coupler which was marked as essential by one amateur. It's a tool that allows you to sample a signal in the forward and the reflected path which comes in handy when you're trying to test and build equipment.
<p>
As mentioned before, your transceiver has some of this equipment built in, or can be set-up to do some of this, so there's no need to go out and spend thousands of dollars to set-up your testing bench on day one, but the day after, I'd add it to my birthday list.
<p>
No doubt that there's many and varied opinion on this. What is your essential testing equipment?
<p>
I'm Onno VK6FLAB
Listen:
How does your gear measure up?
Foundations of Amateur Radio
<p>
When you spend some time in this hobby you're likely to find equipment with similar performance for vastly different pricing. At one end of the spectrum you might compare a cheap $25 hand-held radio to a $450 one. At the other end, a $1,500 SDR or Software Defined Radio against a $4,500 one.
<p>
Those examples are for brand name devices, which generally speaking have published specifications, come with regulatory approvals, a wide user base, reviews and a distribution network. If equipment is found to be operating out of specification, a regulator might seek a remedy or ban the sale of the equipment.
<p>
Those various sources and processes make it possible to compare those devices in a structured way to discover just how deep into your pockets you need to reach in order to acquire a shiny new gadget.
<p>
If you buy any of these devices in the used market, you have no way to determine just how far from the factory specifications the device you're contemplating has deviated. Is that waterproof radio still waterproof, or did the previous owner open up the case and put it together incorrectly? Was it dropped and did a component get damaged? Did the static electricity from a local thunderstorm leak through the circuit via the antenna, or did the previous owner not use anti-static precautions when they looked inside?
<p>
If it actually failed, it's easy to know. If it's still working, absent a laboratory, you're essentially on your own.
<p>
If that's not challenging enough, consider hardware that's released as open source, that is, the original designer released their project, shared the design, a circuit board with component list and specifications. Another person can pick up the documentation and legally build a copy of the hardware.
<p>
How do you know how the two compare?
<p>
Aside from considering how well any design might actually match the real world, how do you know if the original design can be improved upon or not? Did the second builder use the same components, substitute with better ones, or economise on parts they thought were too expensive?
<p>
What happens if the two designers argue with each other about the performance of their respective designs? What if the second design becomes vastly more popular than the original and what if you throw in outright intellectual property theft over the top of all this?
<p>
Now consider the same physical hardware, from the same factory, but using different software. How do you know what impact the software has on the performance of the equipment? For example, one component seen more and more is a chip called an FPGA, a Field Programmable Gate Array. Think of it as a programmable circuit board where updating the software creates a different circuit.
<p>
An FPGA might be used to filter radio signals. With just a software update, you can program different filters and change the actual performance of the entire device. How do you know if the new version of the software has improved or worsened performance?
<p>
What all this lacks is a standard way of describing performance. Not only the kind of standard that's achievable in a laboratory, but one that we can test at home. There's no documentation that I've been able to find that shows how to measure some of this objectively, or even compare your own kit against itself.
<p>
It would be great if I could measure my gear against a standard and you could too and we could compare our respective equipment against each other.
<p>
Even using the laboratory standard measurements, for example the Sherwood Engineering Receiver Test Data, which allows you to compare other tested equipment in the same list, is hard, if not impossible to compare at home by the likes of you and I. Not to mention that Rob NC0B has finally retired after 45 years, so having been licensed in 1961 age 14, there is a good chance that updates are going to become a thing of the past when Rob stops volunteering his time.
<p>
I will mention that this isn't a new thing. Many years ago I spent some time as a broadcaster. One of the very first things I was taught is that you need to set levels to trigger the VU Meter just so. When you make a recording to tape, you're required to generate a 1 kHz tone at a specific level so when it's played back to air, the voice levels will be correct.
<p>
When I became licensed in 2010 I almost immediately discovered that there isn't even a standard way to test if the signal that my radio is putting into the local repeater is the same as that of other amateurs. You'll notice this because you're forever twiddling the volume on your radio when you speak with others on-air because their voice levels vary widely.
<p>
One idea I've been toying with is using a parrot repeater that can measure a signal, allowing anyone who uses the same parrot to compare their equipment.
<p>
How would you approach this increasingly complex problem in such a way that the amateur community can share their results in a way that makes comparison meaningful and useful?
<p>
I'm Onno VK6FLAB
Listen:
Getting Amateur Radio propagation data at home
Foundations of Amateur Radio
<p>
For some time now I've been discussing the potential of weak signal propagation and its ability to create a live map from the data that your own station transmits. There are several systems in place that show a map of where and when your station was heard in the past little while. Using 200 milliwatts, I've been transmitting a WSPR or Weak Signal Propagation Reporter beacon on 10m for the past few weeks.
<p>
At the moment, the furthest away my beacon has been heard is 13.612 km away. That's an 0.2 Watt signal heard on the other side of the planet, on 10m. As distance goes, it's a third of the way around the globe. I must point out that there's no way of knowing if this signal travelled the short path or the long path.
<p>
If you've heard those terms, short and long path but were wondering what they mean, here's how it works. If I get on my bike at my QTH in Perth in VK6 and peddle East until I hit Sydney, I'll have crossed Australia, taken about 184 hours and travelled about 3.746 km. That's the short path. If I head West instead and start swimming, visit Cape Town, Buenos Aires and Auckland along the way, I'll have travelled much further, still made it to Sydney, but taken the long path.
<p>
Radio waves can do the same. Depending on propagation, a signal might take either the shortest route, or go in the opposite direction and take the longest route along the great circle between two stations.
<p>
I'm mentioning this because WSPR doesn't tell you if it's one or the other and if you're using a vertical, it could be either. Even directional antennas might receive a signal from unexpected directions.
<p>
Using one of the mapping tools, wspr.live, I extracted all the sightings of my callsign and all the reports that I'd made from my receiver. It shows that my newest transmitter has now been heard by 11 stations across three continents.
<p>
Those numbers are just the beginning. I wanted to see on the map where these stations were, so, during the week I built a proof of concept world map that I used to visually show the four character Maidenhead grid squares that my station was heard in. I also had a look to see which stations I'd heard over the years and where they were. In all, 771 different stations are in my log, either as a receiver or a transmitter.
<p>
N4WQH heard me on 40m, 18.832 km away when I was using 5 Watts. My station has heard, or has been heard across 331 different grid squares. There's reports across some remote parts of Australia, Japan, India, South Africa, Europe, the United States, several across the Pacific and even a few in Antarctica.
<p>
I wondered how many of the world's grid squares have actually been activated and which station was heard the furthest and how much power was used. Those numbers will have to wait for another day. I initially started using wspr.live which has a neat way of allowing you to embed an SQL query as part of the URL to download the output.
<p>
I was getting some interesting results, so I thought, rather than hammer this lovely resource with my questions, I should download the raw data instead. So I did. Well, I am. Still. It's big.
<p>
As of today, there's 166 files, taking up 60 GB of compressed data, with over 3.5 billion reports.
<p>
The first spot in that data goes to N8FQ who heard WB3ANQ on Monday, the 17th of March, 2008 across 911 km on the 30m band transmitting with 28 dBm, or about 630 mW, reporting a signal to noise ratio of 1 dB.
<p>
Using preliminary data to get started I mapped all the activated squares, each shown as a red box and saw that my entire map was red. At that point I figured that either I've got a bug in my code, or something else is going on.
<p>
To give some context before I share what I found, a Maidenhead locator consists of a combination of letters and numbers. For four letter grid squares, there's a grand total of 32.400 different combinations, running from AA00 to RR99. They're 2 degrees wide and 1 degree high and their width depends on where on the planet they are. At the equator it's about 222 km wide and 111 km tall, at the North and South pole, it's 0 km wide. If you travel between two squares, you might have to move a meter, or the entire width of a grid square.
<p>
Among the report, I found stations who had activated more than one square. That's fair enough, you can move your station and start making noise where ever you like. I found stations with activations across more than a thousand different squares. Before I start pointing the finger, I will mention that if you attach a WSPR beacon to an aircraft, or a balloon, you can legitimately activate plenty of squares.
<p>
When you set-up a WSPR transmitter, you're required to manually enter the locator and mistakes happen. There's plenty of records with invalid Maidenhead locators, typically shown instead is a callsign. Then there are stations that pick desirable locators. This manual entry is also true for the power level and even the callsign, so I'm not outing these stations here, since it's entirely possible that the callsign shown doesn't actually relate to the transmitter or the licensed amateur.
<p>
What does all this mean?
<p>
It means that the information in the WSPR database cannot be trusted. I suspect it also means that the data used to lodge FT8 contacts across the planet can probably also not be trusted. It means that any propagation data you're deriving is likely contaminated by misreporting, deliberately or not.
<p>
As a community, if we want to use this for actual measurements, we'll have to figure out how to make this a trusted resource, because the information that WSPR can bring to propagation is in my opinion extremely valuable.
<p>
I would love to hear your thoughts on how we might fix it.
<p>
I'm Onno VK6FLAB
Listen:
Amateur Radio and the art of getting started ...
Foundations of Amateur Radio
<p>
One of the regular topics of conversation in amateur radio, especially for those new to the community, is where to start? The sheer volume of available options is often overwhelming. If you've never encountered the complexity associated with this amazing hobby the experience can be disheartening and even demoralising.
<p>
In my early years I was results driven. Getting on air, making noise, logging a contact, adding a country, winning a contest, rinse and repeat, get better, do more. There have been numerous occasions when I came home from one of my adventures disappointed, sometimes bitterly so.
<p>
That happened for quite some time, until one day I realised that the journey in and of itself is the reward.
<p>
That might sound disingenuous, so let me illustrate.
<p>
This week I set-up an automatic beacon in my shack that can be heard by stations around the planet, letting me know just how far my signal can travel at any particular moment, using my own station antenna and local propagation. As projects go, it continues to be an adventure.
<p>
As you might recall, I like low power operation, truth be told, I love low power. The smaller, the better. Less is more and all that. I recently completed the first leg of a journey to set-up a permanent beacon. For years I'd been dabbling around the edges. On the weekend, whilst I was in my shack, I'd regularly set-up my computer and radio, set it to WSPR beacon and see what stations heard me. I couldn't turn my radio below 5 Watts, so that's what I used. Before you start, yes, I could turn down the volume, but that involves math and I wanted a result, now.
<p>
It filled a gap using WSPR, Weak Signal Propagation Reporter, like that. For a while, I improved on things by having a receiver set-up that monitored the bands all day every day and recently I turned it back on, with limited success, more on that shortly.
<p>
What I really wanted was to see where my signal was going, not what I could hear. I received a few emails suggesting that a ZachTek WSPR Desktop transmitter, built and sold by Harry, SM7PNV, would be just the ticket. It's a little metal box with USB and SMA connectors. One SMA for the supplied GPS antenna, used for location and time, the other for a transmit antenna. USB provides serial for configuration and power if it's operating in stand-alone mode. Yes, you can operate it without needing a computer and if you want it does band-hopping. After configuring it with things like your callsign and bands, you can plug-in the GPS, your antenna and power it via USB and it will run as an automatic 200 milliwatt WSPR beacon.
<p>
That device in turn prompted a journey to discover a more appropriate antenna, since my current station antenna uses an automatic tuner that won't get triggered by this tiny transmitter. That caused an exploration in how and where to mount any new antenna, with a side-trip into finding a specific anti-seize compound locally. To pick the mounting hardware, I had to get into wind loading, how strong my satellite dish mount might be, how to install and tune a multi-band antenna. The list just keeps growing and that voyage continues.
<p>
I'm tracking the requirements with a project specific check-list, just to make sure that I don't miss any steps and have a place to document new discoveries when they invariably hit me in the face. So-far, so-good.
<p>
The WSPR monitor receiver is currently connected to a generic telescopic dipole, mounted indoors, which in the past gave me a much better result than my station vertical, so I should be able to keep both running.
<p>
Next on the list is to construct a live propagation map for my station, then a way to switch modes on that map, so I can tell if it's worth calling CQ without going blue in the face. I'm also working on a WSPR transmitter for 2m and 70cm, because they are under served in my neck of the woods.
<p>
The takeaway from all this is that whilst there are many steps, and truth be told, that list is growing as I learn, each step is tiny and doable. The only thing that separates me from someone who doesn't know where to start, is this.
<p>
I started. You can too. Anywhere. Doesn't matter. Pick anything that tickles your fancy. Start digging. It's a hobby, not a profession. What ever floats your boat, what ever makes you excited, what ever you're interested in, pick it and do something, anything.
<p>
That's how you get anywhere in Amateur Radio, and Open Source, and life for that matter, just start.
<p>
I'm Onno VK6FLAB
Listen:
One Timezone To Rule Them All
Foundations of Amateur Radio
<p>
Right now it's 10:45.
<p>
That piece of information is unhelpful without any context. I could just as easily have told you that it's 2:45 and it would be just as accurate, helpful and meaningless. The point being that without context, you don't know if I'm an insomniac, drinking morning tea, recovering from a late lunch or putting on my PJs.
<p>
If I'm talking to people in the same room, supplying the time happens within the context of that room, but if the world is our oyster, our room is a little larger and dawn for one person is dusk for another, at the same time.
<p>
Before we could communicate at the speed of light and travel faster than a bullet, time was a relative thing related to the location of the Sun and considered mainly by mariners and astronomers. Even with the advent of increasingly accurate clocks, for most people, noon was when the Sun was at its highest point and the local clock was set to that.
<p>
When our world got smaller, because communication and travel got faster, people started noticing that noon in one place wasn't the same as noon in another place. It became a real problem when people travelled hundreds of kilometres by train in a day. Imagine coming up with a train time-table that takes into account each local version of noon.
<p>
In an attempt to deal with this, railroad managers in the United States established 100 railroad time zones. This malarkey continued until the 18th of November 1883 when four standard time zones were established for the continental United States.
<p>
Of course, being human and all, that was a local solution. Great Britain had already established its own standards for time for England, Scotland and Wales.
<p>
In October 1884, the International Meridian Conference, held in Washington DC, adopted a proposal that designated the Prime Meridian for longitude and timekeeping should be the one that passes through the centre of the transit instrument at the Greenwich Observatory in the United Kingdom and established Greenwich Mean Time, or GMT as the world's time standard.
<p>
Why Greenwich? At the time the United Kingdom had more ships and shipping using Greenwich as their reference than the rest of the world put together and the observatory at Greenwich had produced the highest quality data for a long time. As an aside, on a French map before 1911, 0 degrees was centred over Paris. There are other wrinkles, like the fact that Earth isn't round and as a result the Greenwich Prime Meridian is not quite in the right spot because measurements didn't take into account local variations in gravity.
<p>
In 1972, Coordinated Universal Time, or UTC replaced GMT as the standard for time in the world. It now references the International Reference Meridian, currently about a 102.5m east of the original Prime Meridian passing through Greenwich. It's on the move with reference to land because tectonic plates shift and where it is today is not where it's going to be tomorrow, so don't go looking for a marker to indicate the IRM.
<p>
Meanwhile in the rest of the world people needed to come to terms with how to standardise on what to call time zones. The USA establishing four time zones was just for one country. Depending on who's counting, there's over 200 countries and each has its own set of time zones. Which each might include daylight saving, or not. For some, like VK6, daylight saving was voted on several times. Trials were had and time changes during summer were implemented, then reversed, then reversed again, and again, in total, VK6 did this dance six times and we currently don't observe daylight saving, neither does VK4 or VK8.
<p>
So, not only does 10:45 require location context, it also requires that you know if there's daylight saving happening at that time in that location, which to add insult to injury, doesn't actually happen on the same date each year. It gets better if you consider time in another location. Do they have daylight saving, is it on at the time, do we have daylight saving at that time, how many hours are we apart, when is this actual event and what if we're coordinating efforts between people in multiple locations? Did I mention that summer in Europe is in July and in Australia it's in January?
<p>
In case you're wondering, tracking all this is a massive job currently under the purview of the Internet Assigned Numbers Authority. The person coordinating this, whilst wrangling the politics of naming things, including dealing with warring countries who take umbrage at having their time zone named after "the enemy" is computer scientist Paul Eggert, the project lead of the time zone database.
<p>
War aside, time zones are political. For example, Dublin Time was stamped out by the British as punishment for the Easter Rising.
<p>
If that wasn't exciting enough, to provide local context, we use abbreviations to indicate which location we're talking about. In VK6 that abbreviation is WST, simple enough, Western Standard Time. What if your abbreviation was CST? Is that Central Standard Time in North America, China Standard Time, Cuba Standard Time, or even Australian Central Standard Time. If your local time zone is IST, you could be referring to Indian Standard Time, Israel Standard time, Irish Standard Time or even Irish Summer Time.
<p>
As radio amateurs we hold global contests and we advertise our online club meetings and events. Often, we refer to times and dates that might be understood by an audience of one, but utterly confusing to the rest of the world.
<p>
So, what do you do with this?
<p>
Simple, use UTC. My timezone, called WST, or AWST, is UTC+8. F-troop, a weekly net for new and returning amateurs runs every Saturday morning at midnight UTC, that's 0:00 UTC. No confusion, no daylight saving, everyone can figure out if it's worth being awake for and I must applaud the amateurs from G-land and PA with their contributions in the very, very early hours of their morning.
<p>
So, next time you make some noise about a contest, or any amateur activity that goes beyond the people in your suburb, specify the time in UTC. Who knows, perhaps one day, even the likes of SpaceX, Apple and Google will start using UTC to announce their events ...
<p>
As Goldie Hawn put it: "Well, in my time zone that's all the time I have, but maybe in your time zone I haven't finished yet. So stay tuned!"
<p>
I'm Onno VK6FLAB
Listen:
The Rebirth of Homebrew
Foundations of Amateur Radio
<p>
On the 12th of December 1961, before I was born, before my parents met, the first amateur radio satellite was launched by Project OSCAR. It was a 10 kilo box, launched as the first private non-government spacecraft. OSCAR 1 was the first piggyback satellite, launched as a secondary payload taking the space of a ballast weight and managed to be heard by over 570 amateurs across 28 countries during the 22 days it was in orbit. It was launched just over four years after Sputnik 1 and was built entirely by amateurs for radio amateurs.
<p>
In the sixty years since we've come a long way. Today high school students are building and launching CubeSats and several groups have built satellites for less than a $1,000. OSCAR 76, the so-called "$50SAT" cost $250 in parts. It operated in orbit for 20 months. Fees for launching a 10cm cubed satellite are around $60,000 and reducing by the year.
<p>
If that sounds like a lot of money for the amateur community, consider that the budget for operating VK0EK, the DXpedition to Heard Island in 2016 was $550,000. Operation lasted 21 days.
<p>
I'm mentioning all this in the context of homebrew. Not the alcoholic version of homebrew, the radio amateur version, where you build stuff for your personal enjoyment and education.
<p>
For some amateurs that itch is scratched by designing and building a valve based power amplifier, for others it means building a wooden Morse key. For the members of OSCAR it's satellites. For me the itch has always been software.
<p>
Sitting in my bedroom in the early 1980's, eyeballs glued to the black and white TV that was connected to my very own Commodore VIC-20 was how I got properly bitten by that bug, after having been introduced to the Apple II at my high school.
<p>
I'm a curios person. Have always been. In my work I generally go after the new and novel and then discover six months down the track that my clients benefit from my weird sideways excursion into something or other.
<p>
Right now my latest diversion is the FPGA, a Field Programmable Gate Array. Started watching a new series by Digi-Key about how to use them and the experience is exhilarating.
<p>
One way to simply describe an FPGA is to think of it as a way to create a virtual circuit board that can be reprogrammed in the field. You don't have to go out and design a chip for a specific purpose and deal with errors, upgrades and supply chain issues, instead you use a virtual circuit and reprogram as needed. If you're not sure how powerful this is, you can program an FPGA to behave like a Motorola 65C02 microprocessor, or as a RISC CPU, or well over 200 other open source processor designs, including the 64-bit UltraSPARC T1 microprocessor.
<p>
I'm mentioning this because while I have a vintage HP606A valve based signal generator that I'm working on restoring to fully working. Homebrew for me involves all that the world has to offer. I don't get excited about solder and my hands and eyes are really not steady enough to manage small circuit designs, but tapping keys on a keyboard, that's something I've been doing for a long time.
<p>
Another thing I like about this whole upgraded view of homebrew is that we as radio amateurs are already familiar with building blocks. We likely don't design a power supply from scratch, or an amplifier, or the VFO circuit. Why improve something that has stood the test of time? In my virtual world, I too can use those building blocks. In FPGA land I can select any number of implementations of a Fourier Transform and test them all to see which one suits my purpose best.
<p>
In case you're wondering. My Pluto SDR is looking great as a 2m and 70cm beacon, transmitting on both bands simultaneously. It too has an FPGA on board and I'm not afraid to get my keyboard dirty trying to tease out how to best make use of that.
<p>
What homebrew adventures have you been up to?
<p>
I'm Onno VK6FLAB
Listen:
Defeating the Pitfalls of Predicting HF Propagation
Foundations of Amateur Radio
<p>
As you might know, I like to transmit with as little power as possible, known as QRP operation. My own station runs at 5 Watts, since on HF, that's as low as my radio will go. I could go lower by turning down the microphone gain, which interestingly is how some radios actually operate, but for now, 5 Watts seems to be a good starting point and truth be told, even though I've been here for a while, I feel like I'm learning something new every day.
<p>
One of the largest challenges associated with using low power on HF is propagation on the HF bands which is more fluid than ever. There's plenty of variables. For example, in addition to the day-night cycle, there's Earth's magnetic field, the impact from coronal mass ejections as well as the solar cycle. As that cycle waxes and wanes, or in my case, wanes and waxes, propagation trends are affected on a longer term basis.
<p>
There's all manner of tools to explore this. The Australian Space Weather Service is one of many such bodies that create ionospheric prediction maps showing frequencies and their propagation through the ionosphere. Then there's the derivative ones that use this data to declare if a band is open or closed, spread widely across the globe with little in the way of context, like time, or location.
<p>
There are tools like VOACAP which attempt to predict the point-to-point path loss and transceiver coverage dependent on antennas, solar weather and time and date. They also attempt to arrive at a so-called MUF, the Maximum Usable Frequency, defined as the highest frequency at which ionospheric communication is possible for 50% of the days in a month. The LUF, the Lowest Usable Frequency is defined as the frequency at which communication is possible 90% of the days of the month.
<p>
All these tools have one thing in common. They're predictions and forecasts. They reflect an attempt at quantifying reality. There is a place for this, but my often repeated encouragement of getting on air to make some noise is advice that covers the gap between prediction and reality.
<p>
I've long been a fan of using Weak Signal Propagation Reporter, or WSPR as a tool to measure actual propagation. What I like most about it is that it can be used on your own station, using your own antenna, at any time.
<p>
It occurred to me the other day that there must be a relationship between a WSPR signal and a voice signal. Not a mathematical one, but one that makes the difference between establishing a voice contact with another station and calling CQ until you're blue in the face.
<p>
With that in mind I took a leap and purchased a ZachTek Desktop WSPR transmitter, capable of operating on all the HF bands that my license permits. It was shipped from Sweden this week and it is expected to take more than a month to get to me, likely most of that travelling between Sydney and Perth, but when it does, I'll be able to set up my own in-house 200 milliwatt beacon that will show me just how far my signal goes on the bands that I pick. As an aside, I'm still looking for a similar solution for 2m and 70cm since there are all manner of interesting propagation phenomena associated with those bands as well.
<p>
I'm still digging into how I can best gather the reception data to visualise it and I'm working on a strategy that can send me an alert when a particular band is open from my station at such a level that I can look to operating a particular mode, like FT8, or SSB, or anything that I might choose.
<p>
The data is public, thanks to the various WSPR reporting systems around, so others in my grid square, likely beyond that, will also be able to benefit from my beacon. I'm considering generating a propagation map from my own station and publish that, but it's too early to say what's involved in making that happen.
<p>
Right now I've dived into the rabbit-hole associated with finding a suitable antenna. My current station vertical requires a tuner and I don't think that finding a way to tune my antenna every time the beacon changes band is a good solution.
<p>
I suspect that I'll also need to come up with a way to have two transmitters share the same antenna, but I'll cross that bridge when I need to.
<p>
Once the beacon arrives, it's my intention to start with 10m as my beacon band using my current antenna, since 10m is on the verge of being useful for my QRP adventures and I must confess, I'm looking forward to making a voice contact with the other side of the planet with my station for the first time in a long time.
<p>
What kinds of things can you think of that would benefit from a solution like this?
<p>
I'm Onno VK6FLAB
Listen:
What have you been up to in Amateur Radio lately ... Gary VK2OVA
Foundations of Amateur Radio
<p>
Recently I exchanged emails with fellow amateur Gary VK2OVA. This was his most recent response.
<p>
Hello Onno,
<p>
What have you been up to in amateur radio lately, you ask hahahahahahaha.
<p>
I hope this gives you a good chuckle.
<p>
I decided to construct and erect a full wave 80 meter sky loop. Simple antenna, and I have lots of space to do so with an old tennis court on the block surrounded by existing poles and wire mesh.
<p>
The preparation for me was the key to having an easy path to a successful outcome. First step was to measure out the existing poles for the best fit, measured, then stood back and looked, then measured again, yes all is good, this will work. Made up the ropes and pulleys, rechecked the length and height, yep all good, put the ropes and pulleys in place, ready to attach the insulators. I'm going for four corners with an overall measure of 23 meters long by 17 meters wide. Using a corner feed point.
<p>
Made up a feed point cockatoo deterrent, 90 mil storm water pipe about 15 inches long, split end to end, then zip tied into itself as it wraps around the insulator and feed point. Cockatoos are in abundance here so I had to come up with something to keep them away from the feed point as that seems to be their favourite chew spot.
<p>
Purchased a 100 meter long roll of green and yellow earth wire, thinking to myself, easy as, just cut a measured length off the end and have the correct length left on the reel ready to roll out. Oh but wait, a couple of hams talking on air had a similar situation and it worked out that the roll was shorter than quoted on the label. Best practice here is to unroll it and measure it myself, simple task.
<p>
Now I cannot find my 30 meter tape measure, so I put the task on hold till it turns up. Two weeks later it is no where to be seen, so now I have decided to go with the 8 meter tape measure. After thinking about how to best measure 8 meters at a time I came up with a marvellous plan, I'll put a couple pegs in the ground at 8 meters apart and simply loop the wire back and forth 11 times. After all, this is 88 meters in total and I can simply trim the length to my chosen frequency of 3.620 MHz. I'm feeling very good right about now as I have saved myself a lot of walking and bending.
<p>
Now, the first error pops its little head. After I've cut the wire to length and attempt to lay it out on the ground inside the poles - designated antenna holders - the copper wire reminds me it has a memory. That memory is very adamant, I'm a circle of loops. So yes I now have a birds nest of yellow and green. Have you ever noticed when something like this has a mind of its own, it is, apparently, right. Took at least an hour to unravel it, then several tent pegs, to get this wire to obey me. So I won that battle.
<p>
Because I had measured the wire myself I knew it to be accurate, which proved how wrong I was back when I'd completed the original measure, post to post for potential mast poles. So I reset my ropes and pulleys to the new poles and hoisted the whole lot up in the air, then ran inside to view the antenna analyser. Now something is wrong, I cannot get a meter dip anywhere on HF. Oh dear, I've got a break or bad connection.
<p>
So into trouble shooting mode goes whats left of my brain. Track and retrace. As much as I did I could not identify what was wrong. Only one thing for it I will go back to the beginning and start over.
<p>
Dropped the wire on the ground, pegged it down so it could not get away again. Still could not find my 30 meter tape measure, so out comes the 8 meter tape. But wait, is that a 6 or an 8 on there. Lets settle this, I'll put on my reading glasses just to be sure. Yep it is a 6 meter tape measure, not 8 so therefor I have only got a 66 meter length of wire, oh gosh! Back to square one, move all the pulleys re-measure everything. To correct the problem I had to add on some wire and solder the 2 pieces together. With my new level of cautious approach I managed to get the length perfect at 3.625 MHz.
<p>
I still cannot find my 30 meter tape, nor can I find my 8 meter tape, but the good news is I still have a 6 meter tape measure, actually out of six tape measures that I had it's the only one I can find.
<p>
I've decided I should probably wear my glasses when reading small print, from now on.
<p>
I've been making wire antennas for years and never had an issue. Having just moved here a couple of years ago I'm in a position where size does not impact my antenna choices, hence the ambitious project which took up way to much time and effort.
<p>
And, if this is suitable for sharing please do so.
<p>
Cheers,
<p>
Gary VK2OVA
<p>
<p>
The only thing remaining is to ask you a question.
<p>
What have you been up to in Amateur Radio lately?
<p>
I'm Onno VK6FLAB
Listen:
The Ripple Effects of making change ...
Foundations of Amateur Radio
<p>
During the week a new piece of software was born. It's not going to solve world hunger or address man-made climate change, but it will help some contesters who want to get on air and make noise without actually making noise. From my vk6flab github page you can get yourself a copy of a tiny little bash script with the catchy name of ssbdaemon and use it to launch your very own remote-controlled voice-keyer.
<p>
After making the announcement I received several emails from excited contesters who wanted to thank me for my efforts and I have to tell you, making something that others find useful is very rewarding.
<p>
My announcement also sparked some discussion around using voice-keyers including some who consider that this isn't a useful addition to the hobby.
<p>
More on that in a moment.
<p>
After the code was written, I had to actually, you know, use it. So I hooked up my radio, launched ssbdaemon and fired up my current contest logger of choice, TLF, and attempted to make noise. Unfortunately I wasn't so lucky as to make it all work on the first try. TLF needs to be in CW mode for ssbdaemon to work and someone, somewhere at some point, decided that when you change band, the mode needs to be set, so despite me setting my radio to either Lower or Upper Side Band, TLF would helpfully change it to CW, which actively prevented me from making noise.
<p>
Since TLF is Open Source, I was able to download its source-code and after some trial and error, including discussion with the TLF developer community, I added my own little flavour to my copy of TLF to make it always use sideband. My fix isn't useful long-term, but right now it will make it possible for me to operate my voice-keyer. An alternative would have been to turn off rig control.
<p>
This also sparked discussion on the TLF mailing list about how we might implement this kind of functionality long-term. Those two things, the fact that I could hack my own copy of TLF and discuss long-term updates is why I think that Open Source and Amateur Radio are an obvious match.
<p>
I released my ssbdaemon script as Open Source too, so I immediately benefited from other people looking at it and giving me feedback. As a direct result my code improved, my tool became more useful and those changes were published for anyone to use, immediately.
<p>
At this point I should mention that although I'm using TLF, ssbdaemon is a drop-in replacement for cwdaemon and should work anywhere as a direct replacement, so tools like CQRLOG, Xlog and others can use it with no changes to their code.
<p>
Back to the discussion about the usefulness of this tool in relation to our hobby.
<p>
I think that a tool like mine does a number of things. It achieves the direct purpose that it was built for, making it possible to create a more universal voice-keyer, but it also does other things.
<p>
I set out to make TLF do callsign voice-keying, but in solving the problem, I managed to build a tool that was universal to any station using an external Morse-keyer, regardless of whether or not they were using TLF.
<p>
Several emails commented on the way that I'd come to this solution and observed that this opened opportunities beyond my script, including operating Single Side Band contests remotely.
<p>
As a direct result of my release there's now a discussion underway in relation to how TLF manages band changes. It's not finished, likely it'll go through several iterations and might not be implemented immediately, but the fact that this discussion is happening comes as a side-effect of my script.
<p>
This little script, truthfully almost trivial script, is causing change to happen in unexpected places.
<p>
It did make me wonder if there are little things like this that we can do to bring awareness and activity to other areas, things like man-made climate change and how we might achieve that in tiny unexpected ways.
<p>
As for running a contest with my new voice-keyer, propagation permitting, keep an ear out and let me know how it goes.
<p>
I'm Onno VK6FLAB
Listen:
How to run an SSB contest without using your voice ...
Foundations of Amateur Radio
<p>
As you might know, I consider myself a contester. I derive great pleasure from getting on air and making noise during a contest. It gives me a wonderful opportunity to test my station, hone my skills and work on learning something new every time I participate.
<p>
Due to circumstances I've been away from contesting for a number of years, but recently I was able scratch my itch from my own shack. For 24 glorious hours I was able to make contacts from the comfort of my home, being able to make a cup of tea, eat some dinner, stay warm, catch a nap when the bands were closed and generally have a blast.
<p>
My set-up worked well. Operating QRP or low power, I used a basic contest logger, since I wasn't expecting to be making many contacts. To automatically call CQ, I recorded my voice and set-up a script that played the audio, waited four seconds, then played it again. Using my audio mixer, I could turn that on and off at will and between that and the headset I was wearing I had loads of fun and even made contacts!
<p>
During the last three hours of the contest my partner came home. After hearing me attempt to confirm an exchange for a while, it became apparent that making exchanges, calling CQ and generally talking out loud was going to be an issue in our home, since my shack is within hearing range of the entire house. That or I'm going deaf and my voice is getting louder. I do get excited from time to time!
<p>
For the past several months I've been trying to find a solution and until today I wasn't getting any closer.
<p>
I didn't think I was asking for too much.
<p>
I'm looking for a contest logger, that runs on Linux, that has the super check partial database, knows the contest rules and most importantly, has a voice keyer with the ability to actually voice the exchange itself, as-in, not a pre-recorded audio file, but the ability to speak any callsign and any exchange.
<p>
As an aside, the super check partial database is a list of frequently heard contest callsigns, originally introduced by Ken K1EA, which if used properly, helps you when you're deciphering a callsign on a noisy band. Using it to guess calls and make mistakes can result in significant penalties for some contests.
<p>
The only tool I've come across that does all this in any way is N1MM. It runs on Windows and I have to tell you, the idea of having to buy a new computer, just to run a supported version of Windows just doesn't do it for me. N1MM also doesn't use Hamlib, so my radio needs to be physically connected to the computer. I won't bore you with my weeks of attempts, but it became farcical.
<p>
During my months of exploration I looked at and tried plenty of other tools. Many of them aren't intended for contesting, don't have access to the super check partial database, don't do voice-keying, don't run under Linux, require weird bits of extra software, have little or no documentation and a myriad of other issues like having to compile from source with arcane library requirements, the list goes on.
<p>
One contender that got close was a text only tool called TLF. It got so close that I almost used it for my previous contest. In the end I didn't because it was doing unpredictable things with the display and I had to write my own contest rule file for an unsupported contest which I couldn't test in time to actually use.
<p>
Today I took another look.
<p>
TLF doesn't have a voice-keyer on board, but it does have the ability to interface with a Morse-keyer, which is interesting, since it implies that there is a process that translates callsigns and messages typed in with a keyboard into Morse, which might mean that it may be possible to pretend to be a Morse-key and make voice sounds instead.
<p>
The Morse-keyer software in question is cwdaemon. It accepts text messages from TLF and then converts those into Morse code and then directly controls your radio to generate dits and dahs on-air.
<p>
I started digging through the source code when I realised that cwdaemon might have a debug mode that shows what it's doing. Turns out, not only does it have a debug option, you can also prevent it from keying your radio. Which means that I should be able to get TLF to generate the messages, cwdaemon to show those messages and me to do something useful, like play audio files as appropriate.
<p>
If I pull this off, it will mean that I can operate my station as if I'm running CW, but the radio will be transmitting voice, which makes for a beautiful way to save my vocal chords whilst running a contest without bothering anyone else and do this without needing to install Windows, which frankly, in my book is a win.
<p>
If I succeed, and I think the odds are good, I'll publish my efforts on my github repository for you to use, if you're so inclined.
<p>
I have to confess, when I started this adventure, I was not at all convinced that I could make this happen and I'd all but thrown in the towel. It still quite unbelievable to me that this kind of thing doesn't appear to exist, but if all goes well, it should soon.
<p>
What are you going to be doing for your next contest?
<p>
I'm Onno VK6FLAB
Listen:
The inherent redundancy of a compromise antenna
Foundations of Amateur Radio
<p>
For an activity that's seeped in the art of communication, amateur radio is a diverse collection of people, joined by a common interest and kept together using imperfect language describing an intrinsically complex science in the hope that we can learn from each other to get on air and make noise.
<p>
In this cooperative endeavour, language is important.
<p>
Let me start with a limerick by Arthur Frackenpohl:
<p>
There was a young fellow of Perth
Who was born on the day of his birth
He married, they say
On his wife's wedding day
And died when he quitted the earth
<p>
Stay with me.
<p>
In this day and age, first and foremost, let me give you a short summary, cobbled together from bits and pieces of a new invention, conceived whilst watching the evening sunset in close proximity to the beach.
<p>
What this cornucopia of tautologies has to do with our hobby might not be obvious, but let me illustrate.
<p>
Consider the phrase: "a compromise antenna", as-in, "Oh, I'd never use that antenna, it's a compromise antenna."
<p>
If you've been in this community for any time at all, you'll have heard that phrase and unless someone pointed it out, you might not have realised that it's essentially unhelpful.
<p>
Why?
<p>
Because as I've said many times before, all antennas are a compromise, by definition. This is true at several levels.
<p>
At a fundamental level, an isotropic antenna is a theoretical antenna that radiates equally in all directions - horizontally and vertically with the same intensity. It's infinitely small and operates on all frequencies with infinite bandwidth. It should be obvious, but this antenna cannot physically exist, so every built antenna represents a collection of trade-offs or compromises and no antenna can radiate more total power than an isotropic antenna.
<p>
Beyond that, within the physical constraints of antenna building there are many more compromises. Now this might not be immediately obvious, so let me elaborate.
<p>
Consider a 28 MHz, seven element Yagi antenna. With a 12m boom, a 5.3m reflector element, a turning circle of 7.5m and weighing in at 53 kilo. At 20m above the ground it has a gain of 17.5 dBi and handles 1.5 kW. It's physically capable of withstanding 180 km/h winds. It's a lovely piece of kit and if you have the space, it's absolutely something you might want to receive for your birthday and bolt to a mast somewhere near your radio.
<p>
If all antennas are a compromise, you might ask yourself, how is this beautiful 10m Yagi a compromise?
<p>
For starters, its total radiated power is less than an isotropic antenna. It works between 28 and 29 MHz, but nowhere else. It radiates signals really well in one direction, but not in any other. It requires lots of open space and as a fixed installation, it must be on a heavy duty rotator clamped to a tall mast. To actually acquire and install requires more funds than I've spent on all my radios to date.
<p>
Some of what I've mentioned might be acceptable to you, some not. For example, if you're always portable, this antenna makes no sense. You make choices to select an antenna that's best suited to the job and in doing so, you are introducing compromises.
<p>
Additionally, there are amateurs who would have you believe that a compromise antenna is one with high loss.
<p>
High loss in comparison to what?
<p>
If you live in an apartment block, there's no way that you can fit that 10m Yagi inside your bedroom, so you compromise and use a magnetic loop antenna instead. If you're on the top of a mountain, there's no opportunity to erect a structure, so you use a self-supporting vertical. If you're in a car, you cannot erect a horizontal dipole and drive down the highway, so you bolt a whip to your jalopy.
<p>
All of the choices you make to fit a purpose, an environment, a budget and available material will combine into an antenna that hopefully gets you on air making noise.
<p>
When someone tells you that an antenna is a compromise antenna, what they're really saying is that you made compromises that they're unwilling to make. That's easy to say if you have infinite space, money, experience and opportunity. In other words, they're just blowing hot air.
<p>
The whole point of antenna building is to find a particular set of compromises that suits your situation at the time that you're doing it. The intent of this hobby is to learn what the impact of a particular choice is and how it affects the operation of an antenna in a specific situation.
<p>
Next time you hear the redundant phrase "that's a compromise antenna", ask what compromises they are describing that they don't accept and decide for yourself if they are compatible with what you're attempting to achieve within the resources available to you.
<p>
I'm Onno VK6FLAB
Listen:
Standard Information Exchange in Amateur Radio
Foundations of Amateur Radio
<p>
The art of storing information in such a way that it doesn't devolve into random gibberish is an ongoing battle in the evolution of the human race. Egyptians five thousand years ago were perfectly happy storing information using hieroglyphs. They used it for well over three thousand years, but today you'd be hard pressed bumping into anyone on the street who knows one, let alone one thousand characters.
<p>
Latin fared a little better. It's been in use for over two thousand years, but other than fields like biology, medicine and of course some religions, the best you can hope for is et cetera, mea culpa and my favourite, carpe noctum, that and a few mottos scattered about.
<p>
Using technology to store information is no better. If you have a 3.5 inch floppy disc tucked away in a drawer, can you still read it today and do you know why it's called a floppy disc? What about a 5.25 inch, or 8 inch floppy. What about tape. Do you still have backups stored on DAT?
<p>
Even if you could physically read the information, could you still make sense of it? Can you open a VisiCalc spreadsheet file today? That was invented during my lifetime, first released in 1979. The latest release was in 1983.
<p>
My point being that storing and retrieving information is hard.
<p>
Amateur Radio is an activity that has been around since the early 1900's, over a century of information. We describe our collective wisdom in books, magazines, audio recordings, websites, podcasts, videos and tweets.
<p>
One of the more consistent sources of information coming from our activity is logging, specifically QSO or contact logging. There are bookshelves full of paper log files, but since the advent of home computing, logging now is primarily an electronic affair.
<p>
If you've upgraded the software on your computer, you know the pains associated with maintaining your log across those transitions. If you've changed operating systems, the problem only got worse.
<p>
Currently there are primarily two standards associated with logging, the ADIF and Cabrillo specifications. Both are published ways of describing how to store information in such a way that various bits of software can read the information and arrive at the same interpretation.
<p>
As you might expect, things change over time and any standard needs to be able to adopt changes as they occur. How that happens is less than transparent and in an open community like amateur radio, that's a problem.
<p>
Used primarily for logging contacts, the Amateur Data Interchange Format or ADIF is published on a website, adif.org. There's lively discussion in a mailing list and since its inception in 1996, it's evolved through many versions, incorporating change as it happens. Like the adoption of new digital modes, new country codes and administrative subdivisions.
<p>
Used for contest logging, Cabrillo is published on the World Wide Radio Operators Foundation, or WWROF web site which assumed administration for the specification in 2014. It documents changes as they occurred, like adding contest names, station types and contest overlays. While there's clearly activity happening, there doesn't appear to be a public forum where this is discussed.
<p>
Speaking of public.
<p>
The DXCC, or DX Century Club is a radio award for working countries on a list. ADIF stores those country codes using the DXCC country code number, which is part of the specification published by the ARRL, the American Radio Relay League. The list of DXCC entities is copyrighted by the ARRL, which is fair enough, but you have to actually buy it from the ARRL to get a copy. This is a problem because it means that any future archivist, you included, needs access to a specific version of both the ADIF and the then valid DXCC list, just to read the information in a log file. To put it mildly, in my opinion, that's bonkers.
<p>
Relying on external information isn't limited to ADIF. Cabrillo relies on external data for the format of the Location field which indicates where the station was operating from. Among others, it refers to the RSGB, the Radio Society of Great Britain who maintains a list of IOTA, or Islands on the Air, published on a web site that no longer exists.
<p>
There are other issues.
<p>
It appears that for the Cabrillo specification there is no incremental version number associated with any changes. Version 3 of Cabrillo was released in 2006. There are 31 changes published to update Version 3, but as far as I can tell, they're all called Version 3, so anyone attempting to read a Version 3 log will not actually know what they're dealing with. To give you a specific example of three changes. In 2016 the 119G band name was changed to 123G, which was changed in 2021 to 122G. All three labels refer to the same band, but until you actually start looking at the file will you have any indication about the version used to generate the file.
<p>
Let's move on.
<p>
Contesting. Not the logging or the on-air activity, but how to score a contest. What activity gets points and what incurs a penalty? Do you get different points for different bands, for different station prefixes, for low power, for multiple operators, for being portable and plenty more. Can you make contact with the same station more than once, if so, how often and under which circumstances? What is the exchange, how does it change, if at all? Each of these choices are weighed by contest managers all over the globe and they do it every time they run their contest. For some contests that means that there are dozens of rule versions across the years. To give you some idea of scale, the modern CQWW was first run in 1948 and there's at least one amateur contest every weekend.
<p>
Now imagine that you're writing contest logging software that keeps track of your score and alerts you if the contact you're about to make is valid or not, or if it incurs a penalty if you were to log it. That software is driven by the rules that govern a particular contest.
<p>
Some contest software is updated by the author every time a major contest is held to incorporate the latest changes. Other contest tools use external definition files, which specify how a particular contest is scored.
<p>
As you might suspect, that too is information and it too is in flux and to make matters worse, there is no standard. So far, the tools that I've found that make any concerted attempt at this all use different file formats to specify how a contest is scored and of those, one explicitly points out that their file format doesn't incorporate all of the possible variation, leaving it to updating the software itself in order to incorporate changes that aren't covered by their own file format. That is sub-optimal to say the least.
<p>
Personally, I think that there is a place for a global standards body for amateur radio, one that coordinates all these efforts, one that has a lively discussion, one that uses modern tools to publish its specifications and one that does this using public information with an eye on record keeping.
<p>
I'm Onno VK6FLAB
Listen:
You in the community ...
Foundations of Amateur Radio
<p>
The other day a member of our community proudly showed off their plaque for first place as a Short Wave Listener or SWL in the Poland SP DX Contest. Together with their dad they listened on 80m using a WebSDR and logged all the contacts they were able to hear. Their participation didn't include transmitters, since neither have got their callsigns, yet.
<p>
To me this illustrates exactly what it's like to dip your toes into the world of amateur radio and it's a path that many amateurs have taken to become licensed and transmitting.
<p>
I'm mentioning this because that same short wave listener also won a platinum diploma from the anniversary of Stanislaw Lem's 100th birthday amateur contest.
<p>
If that name sends tingles of excitement down your spine, you're familiar with his work. If not, you might be interested to know that Stanislaw Lem was a world acclaimed Polish writer of science fiction who died in 2006.
<p>
This random discovery, in addition to giving me ideas about opportunities for contests and awards, reminded me of other times when in one setting I've been surprised by information relating to another setting. In this case, science fiction. In previous workplaces I've come across software developers, technicians and managers who outside their roles in computing were active as volunteer fire-fighters, paramedics, writers, stage performers, singers, foster parents and more.
<p>
It occurred to me that we in the amateur radio community spend most, if not all, of our time discussing amateur radio, but that we likely share other interests with our community. I recently discovered other science fiction nerds, a cos-player, there's some volunteer fire-fighters and the like, no doubt there's more.
<p>
My point being that in addition to finding more common ground between us as a community, we also have the opportunity to share our hobby with other people who share our interests. It's hard to imagine that science fiction fans and fire-fighters for example are unable to relate to amateur radio.
<p>
Don't get me wrong. I'm not advocating that you hit the members of your other communities over the back of the head with amateur radio. Instead, think of it as another way to connect to that group.
<p>
The thing that strikes me about our amateur community is the diversity that it encompasses. It means that there's likely plenty of other interests that you will find that bind you to other amateurs and it likely means that your other hobbies and interests might share some of your amateur interests.
<p>
Truth be told, as all consuming as amateur radio is, it's not the only thing that defines you and it's not the only thing of interest to the people around you.
<p>
What those interests are is up to you.
<p>
Only one way to find out.
<p>
Talk with your friends.
<p>
I'm Onno VK6FLAB
Listen:
The sun shines on our hobby in unexpected ways.
Foundations of Amateur Radio
<p>
When you begin your amateur radio journey, one of the first things you learn about that's not directly involved with radios and antennas is the ionosphere and its impact on long distance communications. Immediately after that you are more likely that not to be introduced to the biggest plasma experiment in our backyard, the Sun.
<p>
With that introduction comes information about solar flares, solar flux, sunspots, geomagnetic storms, coronal mass ejections as well as the solar cycle, the solar index and associated propagation forecasts.
<p>
Before I dig further, I will point out that I'm mentioning this with the ultimate aim for you to get on air and make noise, so fasten your seat-belt and let's go for a ride.
<p>
The Sun is big. If it was hollow, it could fit more than a million Earths inside. The Sun accounts for 99.8% of the total mass of our entire solar system. About 73% of the Sun's mass is hydrogen, about 25% is helium and the rest, about 1.69% is made up of all the other heavier elements, both gasses and metals, which add up to around 5628 times the mass of Earth.
<p>
The Sun rotates. Counter-clockwise. Since it's mostly plasma, it doesn't rotate like Earth does. The equator takes about 24 days, the poles around 35 days and because its rotating on an angle of about 7.25 degrees from Earth's rotation axis, we get to see more of the solar north pole in September and more of the solar south pole in March.
<p>
Earth orbits the Sun in a year, but it's not a circular orbit. We're closest to the Sun in December and furthest from the Sun in June. It takes about eight minutes and 19 seconds for a photon leaving the Sun to reach Earth, but that same photon can take between 40,000 and 170,000 years to travel from the core where two atoms were heated and compressed to fuse into a new element releasing a photon and heat. It takes this long because the photon keeps bumping into other atoms along the way. While we're at it, consuming about 4 million tons of hydrogen per second, the Sun will take another 5 billion years to consume all the available hydrogen.
<p>
Whilst we experience the Sun as a source of light on a daily basis, as a radio amateur you know that light is just one tiny part of the electromagnetic spectrum. It should come as no surprise that the Sun is radiating across all frequencies all the time, only some of which is visible to our naked eye.
<p>
As an aside, it's interesting to note that our eyes are essentially translating light into electricity, or said differently, your eye converts radio spectrum into electricity, something which your radio antenna also does.
<p>
Back to the Sun.
<p>
I'm highlighting this level of solar complexity because there's so much talk about the A index, the K index, the SFI, the solar cycle and propagation by experts and amateurs that it's easy to hide behind those numbers and think that a low A between 1 and 6, a low K of 0 or 1 with an SFI above 100 will give you the propagation you're looking for.
<p>
If you think for a moment that the weather forecaster has a difficult job accurately telling you if you need to postpone your outdoor activation because of rain or snow, then you can begin to understand just how complex the interplay between the Sun and our ionosphere is. And I haven't even mentioned that the ionosphere isn't static either.
<p>
It's important to remember that the cute little weather icons you see on the TV news are just as much an indicator of expected weather as the A, K and SFI numbers are for the Sun and its impact on radio propagation. They give you an idea of what might happen, but it doesn't mean that on any given day something completely random and isolated happens that just affects your station and the path that a radio signal took from your antenna to that other rare DX station.
<p>
Just like it would be smart to take an umbrella with you when there's rain forecast, it's also smart to consider the bands you want to operate next time you go on air with a particular solar forecast, but just because it might rain, doesn't mean you're guaranteed to get wet.
<p>
So, in other words, wait for it, get on air and make some noise!
<p>
I'm Onno VK6FLAB
Listen:
We need more glue in our hobby ...
Foundations of Amateur Radio
<p>
Since December 2010 I've been licensed as a radio amateur. For some this seems like a long time ago, for others, it's just the beginning. In my time thus far I've attempted to document and describe my journey and in doing so, I've had the unbeatable pleasure of hearing stories from others who were inspired by my efforts to join, or rejoin the hobby.
<p>
It occurred to me that it's hard to tell when you look at any one amateur if the ink on their licence is still wet, or if the whole certificate is faded and yellowed with time.
<p>
You also cannot tell by looking if one amateur turns on their gear in the car during the daily commute, or if they go out on expeditions to remote locations twice a year.
<p>
The callsign a person holds tells you even less, let alone the class of their license.
<p>
In our community we talk about mentoring and we call such people Elmers, but do we really use this as a way to glue together our hobby as its namesake might suggest?
<p>
As a result of my profile, there's a steady stream of commentary about what I do and how I do it. As you might expect, there's both good and bad, sometimes describing the same thing from opposite sides in equally heated terms.
<p>
I'd like to take this opportunity to point out that playing the man and not the ball will get you completely ignored. If however you have a specific grievance with any technical aspect of what I'm contributing, by all means let me know, but be prepared to provide references because it might come as a surprise, I do research before I open my mouth. That's not to say that I don't make mistakes, I'm sure I do and have.
<p>
Before this turns into a self congratulatory oration, I'd like to point out that all the negative feedback I see all around me does nothing to grow our hobby, does nothing to encourage learning, does nothing to reward trial and error and it doesn't contribute to society at large in any way.
<p>
I'm mentioning this because I also receive emails from amateurs who have left the community, not because of lack of interest, but because of the bullying that they've experienced.
<p>
I know that there are several local activities that I avoid because it's just not fun to bump into people who are friendly to your face whilst being vicious online.
<p>
It continues to amaze me that this topic keeps recurring and that it keeps needing to be called out. One thing I can tell you is that ignoring it doesn't work. I've described previously what you should do instead when you're the subject of such petulant behaviour, but it bears repeating. Say it out loud.
<p>
"Thank you for your comment. I don't believe that it's in the spirit of amateur radio. Please stop."
<p>
Feel free to use that phrase anytime someone in this hobby makes you feel uncomfortable.
<p>
One final observation. If you've not personally experienced this behaviour that's great, but it doesn't mean that it doesn't happen or that it's not endemic. Consider for a moment how you'd feel if you were attacked whilst being active in a hobby you love, for no other reason than that the person attacking you didn't like the wire you were using to construct a dipole or some other equally outrageous reason like your gender, sexual orientation, license class, choice of radio or preferred on-air activity.
<p>
Say it with me:
<p>
"Thank you for your comment. I don't believe that it's in the spirit of amateur radio. Please stop."
<p>
I'm Onno VK6FLAB
Listen:
The Fox Mike Hotel Portable Operations Challenge
Foundations of Amateur Radio
<p>
Getting on air and making noise is what it's all about, so last week, that's exactly what we did. Randall VK6WR, Jishnu VK6JN and I participated in the Fox Mike Hotel Portable Operations Challenge which is specifically scored to deal with power and mode differences between stations by using a handicap system that they liken to playing golf. Having been the winner of the Sir Donald Bradman Award in the Millmerran Memorial Golf Tournament for making the highest score on the day, this speaks to me in more ways than I can say. In case you're wondering, more hits in golf is bad and I'm not a golfer.
<p>
Scoring in the Portable Ops Challenge is based around four different attributes, the power you're using, the nature of your station, portable or fixed, the mode used and the number of transmitters in use.
<p>
To achieve this, you exchange a maidenhead grid square, a combination of letters and numbers that indicates your location on earth, which is then used to determine how many kilometres per Watt are used to make the contact.
<p>
If you're portable, you get a multiplier benefit in the scoring.
<p>
Depending on the perceived difficulty of the contact, you score more points. In this case, SSB is harder than CW, which in turn is harder than a digital mode.
<p>
Finally, the more transmitters you have, the less each contact is worth. Two transmitters, means you score half the points for each.
<p>
With that in mind, a QRP portable station with a single transmitter calling CQ on SSB is the best way to make points and that is something that I'm always up for.
<p>
In our adventure, we opted for a slight change, instead using FT4 and FT8, using 40 Watts, portable, on the side of a hill in a local park and during the four hours we were active, we managed six contacts, one over SSB, the rest using digital modes and we all had several goes at getting the best out of our station.
<p>
Our set-up consisted of a small folding table next to my car with a computer, a radio and a thermos flask with hot tea to ward off the chill in the air. Power was supplied by an 80 AH battery. The radio was an Icom IC-7300 that Randall brought along.
<p>
The antenna we used was a Terlin Outbacker, multi-tap whip that was attached to my car with a 12m counterpoise run along the gutter.
<p>
None of us had ever seen such excellent conditions with such a low noise floor in the middle of the city. We were enjoying the last warm sun of the day from Kings Park in Perth, Western Australia. It's a 990 acre park, larger than Central Park in New York, set aside for public use in 1831 and gazetted as a public park in 1872. The park is open 24 hours a day and features a botanic garden with thousands of species of Western Australia's native flora and fauna, overlooks the central business district, the Swan River and the Darling Ranges and best of all, there's no radio noise. It did get chilly towards the end, but I'm pretty sure we all went home with all our fingers and toes intact.
<p>
Jishnu also brought along his FT-817 and a tiny multi-tap telescopic whip that we strapped to a nearby steel rubbish bin and using that set-up was able to detect and transmit WSPR signals across the globe as part of experimentation with his station.
<p>
One of the unexpected benefits of not yelling CQ into a microphone ad-nauseam was that we were able to continue our conversation, hearing stories from each other and enjoying hot pizza when dinnertime came around without needing to stuff food into the same place where CQ calls were intended to originate.
<p>
My car isn't quite ready to go completely portable, but this little outing again proved to me that portable vehicle based operation has a charm all its own and the Fox Mike Hotel Portable Operations Challenge is going to be on my dance card next time it comes around!
<p>
When was the last time you left your shack and went portable?
<p>
I'm Onno VK6FLAB
Listen:
What's in a sound?
Foundations of Amateur Radio
<p>
Over the past few weeks I've been having my hearing tested. I've had the opportunity to discuss sound in some detail with an audiologist. Today as a result of a collision between a jar of chilli pickles and a tiled floor I've come to the realisation that sound is important in unexpected ways.
<p>
It will probably not come as a surprise to you that sound has an emotional component. Just think of a particular song, or a voice, or something that you've heard previously. The sound of a jack-hammer, or a bell, a horse or a jet, each completely different, impact on your mood. Some sounds are pleasant, others jarring. Some make you feel happy, others make you anxious or even angry.
<p>
For some time now I've observed in myself that there are times when I cannot stand sound and other times when I invite it into my life.
<p>
For example, if there's a HF radio going in the background and I'm attempting to have a conversation with a person in the shack, the sound coming from the radio causes irritation, to the point of needing to turn it off in order to actually hold a conversation. On the other hand, if there's a contest on, I can sit, happy as a clam, listening to HF all day and night, working out what station is calling, and making contact.
<p>
I'm raising this because it occurs to me that amateur radio is unlike broadcast radio where you're expected to actively monitor what is being transmitted. In my experience as a radio broadcaster you're talking into a microphone and the headphones you're wearing are connected to a radio receiver which is tuned to the station on which you're broadcasting. This gives you immediate live feedback on the state of your audio levels.
<p>
As an aside, I once witnessed a fellow broadcaster who didn't feel the need to wear headphones. They were blissfully unaware that their voice was being transmitted into silence because the audio fader on their microphone was down.
<p>
In amateur radio however, we don't often do such things. We transmit blind most if not all of the time. It's rare that we even hear our own voice on-air, let alone hear it in real time. If that's not enough, using sideband, it's easy to modify the sound of a person by changing the frequency slightly, making their voice either higher or lower, just by adjusting the dial.
<p>
It occurred to me that how your voice is perceived by the other station assists in how that station can hear you and make contact.
<p>
Using the local repeater is a good but subtle example. If you've listened for a while, you might have observed that there are stations that are easy to understand and others that are not. Sometimes that comes down to individual accents, but in my experience a much larger impact is caused by the actual transmission itself.
<p>
Is the microphone gain set correctly, is there any filtering in play, is the station on the correct frequency, is the transmitter using the correct mode and other more subtle things like background noise, speaking volume and distance and direction in relation to the microphone.
<p>
We often talk about less being more and you already know that I'm a big fan of low power or QRP operation. Making contacts is absolutely about using the right antenna, the right mode, the correct band and time of day, but the sound coming from your station is just as important.
<p>
If you have the ability to use two radios simultaneously, then I'd recommend that you find a way to either use a local repeater, or a cross-band repeater, or even a remote web-based radio, to hear what you actually sound like on-air, live, and experiment with the various settings on your radio in order to test and improve the quality of your voice.
<p>
Whilst we as radio amateurs don't standardise our signals, though personally I think it would be a great idea, there's plenty of improvement to be had by taking some time out of your next on-air activity to have a long hard listen to yourself.
<p>
I'm Onno VK6FLAB
Listen:
Taking your shack mobile
Foundations of Amateur Radio
<p>
When I first started in this hobby I found myself surrounded by other amateurs who all seemed to have a spare room in their house, or a spare building near their house, or even a property somewhere, dedicated to amateur radio. There was an endless parade of equipment, antennas, tools, workshops, spare parts and the like. Frankly it was overwhelming.
<p>
A decade on, I have some perspective to share on that first exposure. For me the hobby was brand new. I didn't have a family history, there were no amateur friends I'd grown up with, no electronics uncle or anything even remotely resembling any of that. What I was exposed to wasn't a new thing, it represented something that had been going on for years, decades and lifetimes even.
<p>
It quickly became apparent that having a shack was desirable, but in my case, at the time, unobtainable, so instead I did the next best thing I could think of. I built a shack in my car. That was a journey that took several years to make. At the end of it, I removed my radio from the car and moved it onto a spare table in my office.
<p>
I have spent countless enjoyable and sometimes frustrating hours in my car shack and I learnt that it's almost always temporary. If you're not the exclusive user of the car, then your shack isn't always available and in that case it also needs to be family friendly, as-in, no cables, mounts, brackets and the like that can cause damage to a person, or the equipment. This limits the options you have.
<p>
At the end of my car journey, I had a spare battery in the back, the radio and tuner were mounted under the floor next to the spare tyre, there was an antenna mount attached to the car, there was braiding throughout the car, connecting all the body panels together and the remote control head was detachable from a suction mount that doubled as a mobile phone holder. Antennas, one for HF, one for VHF were stowed against the roof lining with a strap around the roof hand grab of the rear passenger. An external speaker was mounted below the head rest of the centre rear passenger.
<p>
What I learnt was that this setup was good for short stints, for mobile operation, for contests on the run and for working DX at lunch time at the beach. Trying to do digital modes, attempting to work a pile-up, or doing several other activities I love were not really feasible and as a result I decided to pull it all out.
<p>
At this point all that remains in the car are the braiding, the control lead, the speaker, the coax and the antenna mount. I plan to rebuild my car shack in the not too distant future. More on that in a moment.
<p>
I moved house and found myself in an office that was perfect for multiple reasons. It was separate from the rest of the living space, so I didn't need to put away stuff. It was big enough to house a dedicated radio table and it's got pretty simple access to the outside world for running coax. It gives me a dedicated place to do radio and have stuff set-up permanently.
<p>
I noticed one thing after having this available.
<p>
I didn't actually get on-air any more than when I was using my car shack. If anything it's less. I think it's because it's also my office and I already spend plenty of time doing office activities that playing radio isn't all that different. I'm going to keep my set-up, but I'm going to go back to my roots and add a radio back into my car.
<p>
It's still a family car, so I need to consider the other uses that it's put to, but I think I can make it work. I recently installed an 80 Amp Hour battery with an automatic charging circuit. It was put there to power the dash-cams, but it was scaled with amateur radio in mind.
<p>
I don't yet know which radio I'm going to put into the car, I really do like my FT-857d, but there are other options available to me, so I'm going to experiment.
<p>
One fundamental change I'm going to make is that the radio will be installed in such a way that it can be easily unplugged and removed. Not because I want to remove it from the car, but because I want to be able to go even lighter, take the radio onto the beach, or into a park or up a summit. I'll likely bolt the whole lot into a Pelican case and make it a mobile go-unit that happens to live in my car.
<p>
I don't think I'll add digital functionality at first, but I'm eyeing off the idea of dedicating an old mobile phone, which is essentially a computer, screen, battery and internet connection in one to the task, but I'll let you know how that goes.
<p>
What I do know, with hindsight, is that less is more.
<p>
I'm Onno VK6FLAB
Listen:
What's in a unit?
Foundations of Amateur Radio
<p>
In our hobby we use kilohertz and megahertz enthusiastically. Sometimes even gigahertz. The other day during a discussion the question arose, what comes after tera, as in terahertz? I couldn't remember, so I had to look it up, peta comes next, then exa, zetta and yotta, derived from the Greek word for eight.
<p>
That in and of itself was interesting, but it turns out that Greek isn't the only language used in attributing SI metric prefixes, SI being the International System of Units. Of the 20 units, which I'll get to in a moment, there's 12 with Greek origins, five deriving from Latin, two from Danish and one from Spanish.
<p>
The units are used to describe how many of a thing there are in base-10, so, a thousand of something is kilo, or ten to the power of three, which gives us kilohertz. A gigahertz is ten to the power of nine and so-on. Interestingly, kilo is derived from the Greek word thousand, but mega comes from the Greek for great. Both hecto, as in hectopascals and deca as in decathlon originate in the Greek words for hundred and ten. The prefix pico, as in picofarad comes from the Spanish word peak and femto as in femtowatt comes from the Danish for fifteen, as in ten to the power of minus 15. Apparently a zeptomole of a substance contains 602 particles, even NASA says so, let me know if you can find a source for that.
<p>
I could devote my entire discussion on these 20 units, adding for example that their naming wasn't all done at the same time, the most recent additions are yotta and yocto, as I said, derived from the Greek for eight, being ten to the power of 24. How's that eight you ask? Well, three times eight is 24. I'm not saying it's intuitive, but there is logic.
<p>
In looking at all these units, and specifically the smaller ones, milli, micro, nano, pico and the like, it occurred to me, is there a way to go below one Hertz, could you have half a Hertz?
<p>
Hertz is the number of oscillations per second, a single Hertz being one per second. Half a Hertz would be one oscillation per two seconds. I started wondering what to look for in discovering if anyone has been playing with this. For the life of me, I couldn't think of what to search for and my experience tells me that if you cannot find the answer online, you're asking the wrong question.
<p>
This morning, with a fresh cup of coffee in my hands, it occurred to me that anyone doing this kind of stuff would be using SI units, so they'd be using decihertz, centihertz, millihertz, microhertz and nanohertz, perhaps even picohertz. So I went searching.
<p>
Turns out that this actually exists. After wading through endless results with conversion tools and dictionaries, there's plenty of research to find.
<p>
The unit decihertz is being used in gravitational wave interferometry, specifically, there's a Japanese, space-based gravitational wave observatory in the works with hopes of launching their three space craft if they can find funding.
<p>
It doesn't end there.
<p>
There are experimental imaging studies being made on malignant and benign human cancer cells and tissues looking at decihertz all the way down to yoctohertz, that's ten to the minus 24.
<p>
Inside Apple software development documentation, in addition to mega, giga and terahertz you can find links to milli, micro and nanohertz as predefined units.
<p>
NANOGrav stands for North American Nanohertz Observatory for Gravitational Waves and it uses the Galaxy to detect them. It was founded in 2007 and is part of a global community of scientists in places like Australia, where the Parkes Pulsar Timing Array is located - yes, that Parkes - made famous from the film "the Dish" and Europe with the European Pulsar Timing Array, combining five separate radio-telescopes, all coming together under the banner of the IPTA or International Pulsar Timing Array.
<p>
The point of my little exploration is that if you're curious about random things, you can often come across activities and ideas you know nothing about and learn something along the way.
<p>
Today I learnt that there is such a thing as a sub-Hertz signal, it's being explored all over the globe with scientists in different fields and it's happening without much in the way of public awareness.
<p>
What did you learn today and which SI prefix didn't I use?
<p>
I'm Onno VK6FLAB
Listen:
Being an equipment custodian
Foundations of Amateur Radio
<p>
A couple of weeks ago an amateur put out a call on the local email discussion list. The message was simple, it read: "I have a 606A HP Signal Generator with a copy of the Operating and Service Manual. It covers 50 kHz to 65 MHz. Free to a good home :-)"
<p>
It's not the first time that such a message has done the rounds, but this time my reply was quick enough for it to be first. Overnight I became the new custodian of a Hewlett Packard 606A Signal Generator.
<p>
A signal generator is a tool that can form a specific carrier across a range of frequencies in much the same way that your amateur radio can. In this case, the HP-606A can cover all the amateur HF bands and everything in between. The signal that's generated is calibrated, that is, it's of a specific power level, very stable, clean and it can be used to calibrate other equipment.
<p>
To set the scene, the HP-606A was released into the wild in 1959. You might call it vintage at this point. It's the size of a modern microwave oven, so I'll need to set aside some bench space in order to actually use it. According to some it's "the best analogue signal generator ever built". It's been in production for decades, with plenty of information to be found online.
<p>
Unlike most modern gear, this equipment comes fully documented by the manufacturer, to the point of user manual revisions depending on the serial number and including essentials like circuit diagrams, parts list, spare parts list, calibration instructions and the equipment needed, how to open it up, tests to conduct after repair, how to conduct regular maintenance and how to replace the tubes in it.
<p>
Yes, I did say tubes, or valves, or glow in the dark electronics.
<p>
At this point I've not yet switched it on. You might wonder why that's the case. This unit has internal voltages exceeding 500 Volt DC, so some care is required. Inside are at least four electrolytic capacitors. Think of each of them as two pieces of aluminium sandwiched together, separated by a piece of foil and electrolytic paste, all rolled up into a cylinder.
<p>
When an electrolytic capacitor is built, the process to convert these components into an actual capacitor involves forming it, which means that the manufacturer applies a specific voltage to the pins of the capacitor and in doing so, causes a chemical reaction which makes all manner of funky stuff happen, including unidirectional conductance, something you're looking for in a capacitor.
<p>
Over time, when not in use, or in my case, in storage, this chemical reaction reverses and the capacitors are back to rolled up aluminium with some foil in between. Powering it up in this state will let the smoke out.
<p>
It turns out that in many cases you can apply the voltage again and reform the capacitor. Apparently, according to the author of Tu-Be Or Not Tu-Be Modification Manual by H.I. Eisenson, applying the voltage for five minutes plus one minute per month of storage does the trick. In my case, I can leave the capacitors in circuit and apply the voltage externally using a Variac, a Variable AC Transformer, loaned to me by Denis VK6AKR.
<p>
Doing the math is a little tricky, since we don't really know when the unit was last powered up, but we're told that it was some time in the last decade, so a couple of hours should suffice, but there are some wrinkles in relation to voltage and managing the step to powering up the tubes, so when I've made it happen, I'll let you know.
<p>
Denis was kind enough to help with opening up the cabinet and having a look-see inside. We noticed that it has previously been expertly repaired with a few replaced components and Denis managed to identify some likely failed tubes, so we're on the scrounge for those. Together we did some initial tests and ran up the unit using low voltage to determine if the various test points were actually showing the proportional voltages that were expected. This isn't like a digital circuit where it either works or not, using a Variac, you can slowly power this up, to a point, and test along the way.
<p>
This brings us to the provenance of this tool.
<p>
I got it from Dave VK6AI and from discussion, we think it came from the estate of Don VK6HK, now silent key. I've met Don's widow who happens to be the neighbour of a friend, so at some point when I have it working I might give her a call. I don't know who owned it before Don. I do know that when it was released, in 1959, it was sold for $1540 US Dollars, the equivalent of $14,000 in today's money, or half a car back then.
<p>
Based on serial numbers, this HP-606A appears to have been manufactured between October 1961 and August 1966, so it's older than I am. In case you have extra information, the serial number is 009-01180 and my email address is cq@vk6flab.com. If you have spare valves, a 12B4A is high on the list, get in touch.
<p>
While Denis and I were exploring inside the guts of this function generator, we were at the clubhouse of the local WA VHF Group, surrounded by other amateurs who were doing their own thing. At one point I looked up and noticed two amateurs in deep discussion about using a piece of software, CHIRP, to program a handheld radio on a Windows 10 laptop, whilst I was sitting across the table, picking through the guts of a 1960's piece of equipment. It made me smile, thinking about the history that those two extremes represented.
<p>
Becoming the custodian for such a significant piece of equipment isn't for everyone. I've been given suggestions to toss it out and buy something modern, but I have to confess, even though I'm software personified, SDR to the core, well, aiming to be, this piece of equipment does something for me.
<p>
What equipment do you own that makes you go all misty eyed?
<p>
I'm Onno VK6FLAB
Listen:
All the things that aren't amateur radio...
Foundations of Amateur Radio
<p>
Recently I illustrated the diversity of our community by highlighting social media posts made to a single community over a 24 hour period. Each reflecting a different aspect of our community.
<p>
It occurred to me that although those things are amateur radio, some more obviously than others, there's a whole other side of the community that isn't amateur radio.
<p>
Look at radio astronomy for example. One of my friends is an astronomer and we've been having loads of fun learning from each other. I'm getting exposed to concepts like Fourier transforms, interferometry, sampling and plenty of the mathematical concepts that underlie my interest in amateur radio.
<p>
Then there's things like physics. While I've always been interested, long before I met my physics teacher in high-school who helped me kick off a career in computing, I've been playing with light bulbs, batteries, disassembling old hardware like the valve radio that I was given when I was about twelve or so.
<p>
There's the continued curiosity about audio. I've been making mix-tapes since I was nine, and that has blossomed into an ongoing interest in audio production, some of which is reflected in my weekly podcast and fuelled by my hearing loss.
<p>
My interests outside amateur radio have always been wide and varied. I've learnt to fly an aeroplane, learnt to navigate a sailboat, learnt to drive a truck, installed satellite dishes in the bush and built a mobile satellite ground station, built software solutions for piggeries and bakeries, provided logistics for remote outback events, built vehicle mounted GPS tracking and mapping solutions and I continue to read articles as they come my way.
<p>
What amateur radio has given me is a context, a framework if you like to bring together these wide ranging fields and make them hang together.
<p>
An obvious, though simple example, is learning the phonetic alphabet. In amateur radio it's a given that you'll need to learn that so you can effectively communicate using a poor signal path, but my phonetic learning predates my amateur radio exposure by at least a dozen years. In order to pass my aviation radio certificate, I was required to learn the phonetic alphabet before I was allowed to use the radio.
<p>
It's only a small example, but it's illustrative on how, for me at least, amateur radio is the glue that binds it all together.
<p>
It happens at other levels too. I've mentioned in the past that looking at a television antenna on the roof of any house before getting a license was a non-event. Today I can't look without thinking about propagation, how the antenna is aligned and if it's installed back-to-front or not. Once you know a thing, it's hard to un-see, or unlearn the background of it.
<p>
The same happens when I spot an antenna in the wild, stuck to a lamppost, or bolted to a random roadside cabinet. Previously they would go unremarked, today I wonder what information they're transmitting or receiving, what band they're operating on, who owns the equipment and what interference they might be causing or experiencing in their environment.
<p>
I have a growing interest in computer controlled manufacturing like 3D printing, laser engraving and CNC and spend some of the available time in the day learning about how that works, how to improve things and I wonder about how the speed of communications between the various components create an RF field of some sort and what that does to other components and circuits.
<p>
As a final experience, recently I had a medical procedure where there was a notice supplied with the logging hardware that specifically called out amateur radio as a source of electromagnetic radiation and that I was required to refrain during the process due to a potential failure of the equipment. If anything, for the first time in a long time, I felt that there was a visible link between my hobby and the rest of the community, since that notice was given to every single person, not just the radio amateurs.
<p>
Some links between amateur radio and the rest of the world are visible and some are not. What kinds of interactions between the hobby and society at large have you come across?
<p>
I'm Onno VK6FLAB
Listen:
The diversity of our hobby is breathtaking.
Foundations of Amateur Radio
<p>
You've heard me say that amateur radio is a thousand hobbies in one. It's not my idea, but it speaks to me in ways that are hard to articulate. Today I found a way that might give you an inkling just how vast this community is.
<p>
One place where our community gathers is on-air, but it's not the only place. There are clubs, websites, email lists, video channels and other outlets all catering for different amateur radio users and their interests. One such place is the social media site Reddit. In the so-called amateurradio sub with currently over 88 thousand members, there is a lively community discussing many of the different aspects of our hobby.
<p>
Over the past 24 hours, 23 posts were made in that single community.
<p>
"Thanks, K-2722 hunters", was a photo about activating Carolina Beach State Park, as part of an activity called Parks on the Air, or POTA. To participate you can either go to a park, set-up your station and make contacts, or you can stay at home and listen out for people who are doing that.
<p>
"It's not high-high, it's hee-hee", a meme around the sound that the Morse Code generates when you send the letter H followed by the letter I, commonly considered laughter.
<p>
"Why don't scanners have FM radio?", a discussion around the perceived lack of FM mode on scanners.
<p>
"Help with TYT MD-380 CPS", a question from an amateur who purchased a new radio and is looking for software to program it.
<p>
"Portable on the Space Coast. QRP on a speaker wire antenna.", a video of an amateur making an activation in Florida and showing off their set-up.
<p>
"Could not hit DMR repeater", an amateur sharing that they figured out that they couldn't hit a repeater because they had their radio set to low power and wanted to share that with the community.
<p>
"Antenna advice part 2", asking about how to set-up antennas for dual use, how to amplify the signal, use rotators and what kind of coax to use.
<p>
"ISS SSTV Aug 6-7 145.800 MHz FM", linking to a news item announcing slow scan television coming from the International Space station in August.
<p>
"FT-3DR APRS message question", exploring the specifics on how Automatic Packet Reporting System or APRS messages are sent. Think of it as global distributed SMS via amateur radio.
<p>
"Is it okay to leave a handheld radio on while it's on its battery charger 24/7?", with answers to the question that's puzzling one owner of a radio.
<p>
"Extra test question", asking about how to learn for the test and wondering if the techniques needed are different when compared with obtaining the "tech" exam.
<p>
"Just got my first radio! Now to prep for the test, but first a question about saving time after I pass it...", asking about how to register before the test to speed things along.
<p>
And that's just over half way there.
<p>
"Maldol TMH-21 / TMH-71 handhelds - any info?", asking about a new to them radio from around 2007.
<p>
"2021 Berryville, VA (US) Hamfest - any reddit community members going?", looking for others going to the first hamfest in their region for a long time.
<p>
"CB Radio is Going FM! Why is the FCC Doing It?", linking to a video that discusses the changes on how CB radio is getting another mode.
<p>
"What is the 'right' way to learn morse?", the age-old question, one that I'm still am working through.
<p>
"Sidetone distorted on QCX mini? How do I fix this? It gets better or worse when I move the radio around, but the problem doesn't go away. Anyone else's QCX do this?", with a video showing the issue.
<p>
"Aluminium roof trim + HF dipole", with a question on what kind of effects might happen as a result of the combination of the two.
<p>
"Never owned a Radio be for please help lol. I got 2 of these on the way any tips for beginners? [sic]", excited new owner looking for advice.
<p>
"I finally got my qsl cards printed!", with pictures to show the artistic prowess involved.
<p>
"Legality of transmitting digital data over FM audio", asking about the specifics on how data may or may not be transmitted in the United States.
<p>
"It's no pie plate on a kayak, but you gotta work with what you have, right?", showing off a frying pan as a magnetic base. If it works, it's not silly at all.
<p>
"Very New Here", asking about how to explore radio waves.
<p>
Those 23 different posts are all about amateur radio, from one single community, on one day. Each post from someone finding their way in the community, discussing something that's important to them, sharing their experience and contributing to that community. Reddit alone has at least a dozen amateur related communities, covering electronics, specific radios, amateur software development and more.
<p>
The thing about this hobby is that it's different things to different people. For some it's about getting on air and making noise, for others it's learning about whatever comes their way. This hobby is so vast because it touches so many aspects of life, it innovates, leads and contributes in ways that are often invisible and that's why it's so engrossing.
<p>
What's your latest interest in this hobby and what keeps you coming back for more?
<p>
I'm Onno VK6FLAB
Listen:
How are contests scored?
Foundations of Amateur Radio
<p>
The essential purpose of an amateur radio contest is to get on air and make noise. Each contest has a set of rules on how they intend to achieve this. An integral part of the rules is the idea that you establish a contact, a QSO, with another station and exchange some predefined information. Likely the callsign, a signal report and often something else, a serial number, the age of the operator, a maidenhead locator or the CQ or ITU zone. I'll race past the discussion around sending 5 and 9 as a standard signal report and move right along.
<p>
To validate your activity, you record this information in a log and after the contest has concluded, you share your log with the contest organiser who collates and processes the submitted logs to determine a winner. As a participant you look for your callsign on the results page and if you're lucky you get some form of trophy, a certificate, a plaque, or more often than not, a PDF. An amateur radio contest is not a particularly high stakes competition.
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Recently I asked a group of contesters a question: "How do you learn why a QSO was excluded from your score?" I asked because one of the eight contacts I managed during a recent contest was disallowed, leaving me with an unexplained discrepancy between my log and the results. I will note that this entry didn't affect my ranking, I won my category, mainly because I was the only entrant - hah!
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Depending on whom you ask, this is either a simple or a complex question.
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The simple explanation states that if the contact isn't in the log of both stations it's not a valid contact. This interpretation was extremely popular in the group I asked.
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It was not the only answer I received.
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When I spoke with individual contesters they came up with different answers to my original question.
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For example, if I log everything right, if I'm using a serial number, the number increments each time and my log shows that, then my log entry should be valid, even if the other station didn't log it correctly. Note that I said log, not copy, as-in, they repeated back what I gave them, but logged it incorrectly.
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I also wondered what would happen if I was using a club-station callsign and accidentally called CQ with my own callsign and a station logged that callsign instead of the club-station. Should they be penalised because they logged what was actually exchanged?
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There's more.
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For example, what happens if the times are not identical? Based on the simple explanation, this would not be a valid contact, so you would not get recognition for this exchange and in some contests an invalid contact will produce a penalty to both stations.
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Another variation to the simple answer occurs if the contest organiser doesn't receive a log for every station and as a result, some contests set a maximum number of contacts for stations without logs.
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All this came within the context of attempting to discover how log validation happens, who decides what's valid and what rules are used. During my group conversation, two contest managers shared how they scored their particular contests and showed that they attempted to award the benefit of doubt to each station. One decided after the discussion to change their interpretation to the simple explanation I've already looked at.
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I wanted to know if there was any standard and other than pointing vaguely in the direction of a few large contests, I didn't actually manage to find any definitive discussion on how this works, if it's universal, which I suspect it isn't, and if it changes over time, which I know it does.
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The largest annual contest is the CQ World-Wide. In a 2012 blog post the contest committee discusses the time window of a contact and explains that they allow a 15 minute window, so as long as both contacts agree within 15 minutes, the QSO is allowed. That post also pointed out that if the time for one station was out by 45 minutes, none of their contacts would be allowed and anyone who made contact with that station would by implication get a penalty.
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Clearly there are variations on how this is handled.
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I asked if there is validation software for logs that checks this and if that software is open source so others can look at how decisions are made and see how these evolve over time. Is there an arbitration that goes beyond the standard phrasing in most contests: "The decision of the contest committee is final."
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I was told that this wasn't necessary and I should focus on more practice. I beg to differ. I've been contesting for a decade now, I have plenty of winning certificates on my wall. I'd like to improve my skill and I'd like to learn why and how my contacts are disallowed and I'd like others to be able to do the same.
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Log checking software is written by humans who interpret the rules and write software to conform to those rules. In order to see what rules are in place and to validate that, the source of that software must in my opinion be open and transparent.
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As a community we sit at the boundary between professional communications and a hobby and we often use the idea and concepts of a contest to argue that this is the best way to hone skills and to make you a better operator in case of an emergency, but if you cannot actually learn from your mistakes, if there is no discussion on how decisions are made, if there's nothing beyond simple answers, then are we really striving for improvement or just set in our ways?
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For the record, I think that if a contest log is off by 45 minutes throughout the entire log, software should pick that up, award the contacts and point out the mistake to the person who didn't set their clock correctly, especially since time is not exchanged during any contest I know. I also think that if a station logged what was actually said, there is room for that to be considered a valid exchange, but then I've only been an amateur contester for a decade, so I have plenty to learn.
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I'm Onno VK6FLAB
Listen:
Share if you care...
Foundations of Amateur Radio
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When you explore the landscape of amateur radio you'll discover an endless array of innovation. There's websites with photos and descriptions of activities, places discovered and lessons learnt. If you watch the growing collection of YouTube channels you'll discover videos describing what people have been up to, commenting on videos they've seen and you'll start to notice that people all over the community are pinging off each other. Social media does the same.
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If you read an amateur magazine, or a book, you'll unearth references and counter-references, links and credits, descriptions gleaned and tests made, all of them interlinking and adding to the knowledge base that underpins the amateur radio community and society beyond it.
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The same is true for on-air activity. Look at contesting for example, you'll hear descriptions from other contesters, sharing their lessons learnt which potentially influence how you do your next contesting activity. The same is true for working DX, operating any digital mode, running an on-air net, running a SOTA activation, anything.
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The point being that you are influenced by others and everything you do influences somebody somewhere else who in turn influences the next person who might then influence you. On and on the chain grows.
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This chain of knowledge goes back to the early science in our hobby, the works of James Clerk Maxwell who for the first time brought electricity, magnetism, and light together as different manifestations of the same phenomenon in 1864.
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The reason we know this is because he published his work and without needing to leave home to see the original, anyone can read it today from the comfort of their living room thanks to the PDF that's on the Royal Society web-site.
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The point being that Maxwell documented his work and shared it with the world.
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In our hobby we've gone through the process of making our equipment from unobtainium, requiring that the actual components were constructed before you could actually put them together and use them for their intended purpose. We then went on the scrounge for parts from other equipment, acquiring surplus gear and through a phase where you could buy new components off the shelf and attach them to an etched circuit board. That evolved into being able to design a board, ordering it online, having it built for cents and shipped to our door.
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Today an increasing component of our hobby evolves around software with its unique property of transience.
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Unlike physical components, software is intangible. You imagine how something might work, you describe it in an imaginary language, convert it into something that can be run inside a computer, and if you did it right, the outcome gives you the basis for your next experiment.
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When software reaches a certain level of complexity it becomes impossible to remember. You tweak something over here and something over there changes and unless you can keep all that together inside your brain as a cohesive imaginary model, you quickly run into a brick wall.
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If you're a software developer you've likely heard of tools like CVS, SVN and git. They are examples of revision control. They're used extensively in software development, but increasingly they're being used to track changes in documents, legislation and places where change is constant.
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As an aside, if you load the various versions of legal requirements of your license into revision control, you'll quickly discover that your license is slowly evolving over time, for better or worse. From personal experience, I know doing that for the Radiocommunications Licence Conditions in Australia was very interesting indeed.
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Each of these tools gives you the ability to tweak something, track it and if it doesn't work out, revert to where you started your experiment. It's a little like using a soldering iron and a soldering wick, physical undo for experiments.
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When I talk about Open Source software, I'm not only talking about the ability to look inside and add functionality, I'm also talking about accessing the history that goes with that.
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Open Source software generally only works if it comes with a revision history, a trail of discovery outlined right there on your screen showing what worked, why and how it came about. There's often options for showing who made what change, which changes happened at the same time and the ability to extract that particular change. All essential ingredients for experimentation.
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Closed Source software does all those things, but privately. It too likely uses revision control tools, even the same ones as Open Source, but the discoveries are held in-house, behind closed doors, used by a select few. The software evolves inside the organisation, but there's no insight for or from the outside world.
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Of course, everyone is entitled to keep their stuff secret, but if you want to make a contribution to society outside the life of your walled garden, the only way forward is to publish and share your work like scientists have been doing well before the Royal Society held its first meeting on the 28th of November 1660.
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Share if you care...
<p>
I'm Onno VK6FLAB
Listen:
What Open Source means to our hobby and why it's important.
Foundations of Amateur Radio
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For much of the past month I've been attempting to articulate what Open Source Software is, why it's important, how it's relevant to our hobby, how it works, how software is different from hardware and why you should consider if the equipment you buy comes with source code or not. I'm finding it difficult to separate out the issues since they all hang together in a cohesive clump of ideas and concepts.
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So, let me go sideways to set the scene.
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There is a movement that asserts the right to repair our own things and to ensure that manuals and diagnostic tools used by manufacturers are made available to the public.
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For many radio amateurs that might sound quaint and obvious, since for much of the hobby that kind of information was not only available, it was expected and assumed to be available. You can get the circuit diagram and testing procedures, the alignment process and the list of required test equipment for most if not all amateur transceivers today and truth be told, if that testing gear isn't available, we tend to build or scrounge our own.
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Compare a Yaesu FT-857d and an Icom IC-7300. They're radios from different generations, use different technologies, are made by different manufacturers and come in different packaging.
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Both radios have user manuals, circuit diagrams and documented testing and alignment processes, but they're not equivalent even if they look the same.
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The 857 is constructed from discrete components and circuits. There's a microprocessor on-board, the source code is not available and updates are issued by the manufacturer if and when it sees fit. Its function is to control and sequence things, selecting band filters, switching modes, updating the display and control serial communications. While integral to the functioning of the radio, the microprocessor itself is used for command and control only.
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Inside the 7300 you'll also find discrete components. There are circuits, filters and the like and while individual components have reduced in size there are many of the same kinds of functions inside the radio as you'll find on an 857. The microprocessor inside the 7300 is more advanced than the one inside the 857. The source code is also not available and updates are issued by the manufacturer when it sees fit.
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If that was all there was to it, I would not have spent a month attempting to capture this. Suffice to say that looks are deceiving.
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The microprocessor inside the 7300 does the exact same things as the 857 with one minor difference. It now also forms part of the signal input and output chain of the radio itself.
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Let me say that again.
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The computer that is the heart of a modern radio is an integral part of the signal processing of the radio. Where in a traditional radio the microprocessor was switching circuits on and off to process the signal, the modern solution is to do all the signal processing using software inside the microprocessor itself. If you want to get technical, an FPGA is doing much of the signal processing, but that too is driven by software.
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Where previously you had access to the circuit diagram that would show you what was being done to the signal, today you have a magic black box that does stuff completely outside your control.
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If you want to know how an SSB or FM signal is decoded on the 857, the service manual will helpfully point you at two chips which provide those specific functions. It describes how the signal comes into the chip and how the signal is processed once it leaves the chip and if you need more, you can look online to find the specifications for each chip to see precisely what they do and how they work, complete with equivalent circuits and specifications.
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On the other hand if you wanted to know the same information for the 7300 you'd be out of luck because if you dig deep enough, following the signal path, eventually you'd end up inside the microprocessor where software is making that happen. There's no description on how this works, what the circuit equivalent characteristics are, there's no way to change how it works, no way to set parameters, no way to see inside and no way to experiment.
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This is a problem because it means that you've got a solution that's no longer operating in the spirit of amateur radio. It's not open for experimentation, it's not subject to review, there's no way to test, no means to improve, no way to do anything other than what the manufacturer decided was appropriate.
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For example, if I wanted to modify the FM pass-band width on an 857, I could update the FM demodulation circuit by replacing a couple of components. On a 7300, I could not because there is no circuit. The FM demodulator is described in software that I don't have access to and Icom has decided that the FM pass-band is fixed.
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If the software was open however, I could add this function and make it available to anyone who would like to experiment.
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At this point I'd also like to observe that the Icom user manual states that inside the IC-7300 it uses open source "CMSIS-RTOS RTX", "zlib" and "libpng" software, so Icom is benefiting from open source efforts, but not sharing their own.
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This is not an Icom only problem, this is a specific issue around open source versus closed source and while you might think that the right to repair and open source is something that's not relevant to you, I'd like to invite you to consider what the implications are for our hobby. Are we going to go down the road of button pushers, or are we continuing our role as inventors and experimenters?
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I'm Onno VK6FLAB
Listen:
What mode is that?
Foundations of Amateur Radio
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The hobby of amateur radio is about communication. When you go on-air and make noise, you initiate a communications channel, sending information out into the world and hoping for another station to receive and decode what you sent. The channel itself can be used in an infinite number of ways and each one is called a modulation mode, or mode for short. The popular ones come with most radios, CW, AM, SSB and FM.
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Those few are not the only ones available. In fact as computers are being integrated into the radio at an increasing pace, signal processing is becoming part and parcel of the definition of a mode and new modes are being introduced at break neck speed. I've talked about WSPR as an example of one such mode, but there are many, each with their own particular take on how to get information between two stations.
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As you listen on the bands you'll increasingly find yourself hearing a bewildering litany of beeps, pops and clicks. Some of those are due to ionospheric conditions, but many are different modes that are being experimented with across our spectrum.
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If you have access to a band scope, a way of visualising radio spectrum, you can actually see the shapes and patterns of such signals over time and getting to that point can be as easy as feeding your radio audio into your computer and launching a copy of fldigi or WSJT-X.
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Every mode requires a specific tool to decode it and with practice you'll discover that there is often a particular look or sound associated with a mode. Over time you'll confidently select the correct decoder, using your brain for the process of signal identification.
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Of course if you don't have access to the library in your brain yet, since you've only just started, or if the mode you've come across is new, you'll need another library to discover what you found. There is such a library, the Signal Identification Wiki. It's a web-site that hosts a list of submitted signals, grouped by usage type, including one for our community.
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On the amateur radio page of the Signal Identification Wiki there are over 70 different modes listed, complete with a description, an audio file and a spectrogram. With that you can begin to match what you've discovered on your radio to what the web-site has in the library and determine if you can decode the incoming information.
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I will mention at this point that the Signal Identification Wiki is far from complete. For example, the Olivia mode has 40 so-called sub-modes of which about 8 are in common use. Each of those sub-modes looks and sounds different. The wiki shows only a single line for Olivia.
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I'm pointing this out because the wiki allows you to submit a mode for others to use. If you have a signal, either by recording it off-air, or better still, recording it directly from the source, consider submitting it to the wiki so others can benefit from your experience.
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If you've come across a signal and you cannot figure out what it is, there are other places you can go for help. The four and a half thousand members of the /r/signalidentification sub on reddit will happily look at and listen to your signal and try to help. Make sure you contribute some meta data like the time, frequency and location to accompany the spectrogram and audio.
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You might have come to this point wondering why I'm encouraging you to use and contribute to the wiki and ask for help on reddit. Amateur radio is about experimentation. We love to do that and as we make signal processing easier and easier, more people are making new modes to play with.
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The speed at which this is happening is increasing and as an operator you can expect to come across new signals. I remember not that long ago, it was last month, tuning to an FT8 frequency and the person I was with asking what that sound was. They'd heard it before but never discovered its purpose, even though FT8 has been with us since the 29th of June 2017.
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What interesting signals have you come across and how did you go with decoding them?
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I'm Onno VK6FLAB
Listen:
When you share the hobby grows ...
Foundations of Amateur Radio
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Recently I received a lovely email from Simon G0EIY, who reminded me that there is a voice-keyer that fits into a microphone. It was designed by Olli DH8BQA as a replacement for a standard Yaesu MH-31 microphone. I'd come across this a while ago and for several reasons put off actually ordering one, but Simon's encouragement tipped me over the fence and I've placed my order.
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What I'm expecting to arrive at some point is a kit that has the minuscule surface mount components already soldered to a circuit board, leaving a couple of individual components ready for my soldering iron abuse. I'll let you know how it goes.
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This little experience reminded me that I've been stumbling across solutions like this for years, an amateur with an itch to scratch and the drive to do something about it.
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For example, Paul KE0PBR likes to operate satellites and in doing so amassed a collection of frequencies. Since the Doppler effect alters the actual frequency depending on the satellite coming towards you or moving away from you, there are corrections that need to be done. If you're in the field, this is something that you might struggle with, so Paul created a Frequency Cheat Sheet.
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If you're looking into magnetic loop antennas, you'll quickly encounter a spreadsheet made by Steve AA5TB that will get you started with the parameters for designing and building your own magnetic loop.
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The popular VK Contest Logger, known colloquially as VKCL was built by Mike VK3AVV. It's a simple to use logging tool that has a large collection of rules for different contests and Mike often brings out a new version to incorporate the latest rule changes just before a contest. It even incorporates a station log.
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If you've come across apps like DroidPSK, DroidSSTV and DroidRTTY, they're the brain children of Wolfgang W8DA. The increasingly popular Repeaterbook maintained by a global community of volunteers is the work of Garrett KD6KPC.
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I've lost count of the number of radio amateurs running an online shop where you can buy gear, or kits, or circuit boards, components, antennas, software and the like, not to mention an astonishing collection of professionally built tools like antenna analysers, filters, amplifiers and more.
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It's said that amateurs are notorious for their short arms and deep pockets. I like to think of it as a discerning and informed customer. It's easy to sell snake-oil to the masses, it's been going on for centuries, it's much harder to do that when the person you're selling to knows how the thing you're selling works and knows how to read a data-sheet, let alone ask awkward questions when the need arises.
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Before I go on I will mention that the people I've named here are unaware of me doing so. I've not been approached by any of them to mention their name and I have no relationship, other than being a happy customer. I'm saying this out loud because this podcast goes out on amateur radio repeaters all over the world and commercial use of amateur radio is strictly prohibited.
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You might have gotten to this point wondering why I'm even taking the time to highlight some of the efforts I've come across and the reason is very simple. This activity is everywhere, you just have to look. It's not like Olli, Paul, Steve, Mike, Garrett or Wolfgang shouted their involvement from the rooftops, it's just that the information is available if you care to look. Remember, these people are radio amateurs just like you and I.
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That's important because the difference between a tool that you're using that you built, sitting in your shack or on your computer and that of the people I've named is that they took an extra step and shared their efforts with the community. Some amateurs are making a living from this hobby and I applaud their efforts, for the rest of us, me included, that's often not the point.
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Invention is happening all over the world, right now. You are doing it, despite your protestations to the contrary. You might have made a PDF that you carry around during a contest, or it might be a calculator you knocked up to figure out how to build something. It might be a circuit diagram, an app, a how to guide, a map or a video. All of these things are creations that can be shared to increase the amount of innovation that happens by people bouncing ideas off other ideas.
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In 1675, Sir Isaac Newton said: "If I have seen further it is by standing on the shoulders of Giants."
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You are one of those giants and the person who uses your contribution to make their own is standing on your shoulders.
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What are you waiting for?
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Publish, share, document, photograph and make available, it's how society makes progress and it's how amateur radio stays at the forefront of innovation.
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Get on air and make noise is not purely restricted to the RF spectrum.
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I'm Onno VK6FLAB
Listen:
Here be Dragons, venturing into uncharted territory ...
Foundations of Amateur Radio
<p>
Sometimes when you head into uncharted territory, you gotta laugh at yourself from time to time. Last weekend I participated in a contest, something I enjoy doing as you might recall. To simplify the process of setting up in a vehicle I'd proposed a bold plan to save space and reduce complexity. I was anxious about reducing the amount of technology because I'd come up with a plan to use a paper log to track my contest contacts.
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I had visions of operating for the best part of 24 hours and making hundreds of contacts. This was based on the fact that in 2016 I'd done this same contest on my own and made a 138 contacts and scored 18221 points, having moved 17 times.
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I'd also done the contest in 2018 and for reasons I don't recall, I made one contact over 8 hours.
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That right there should have been a warning sign that I might not quite get the result I'd been fearful of.
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Blissfully unaware of the adventure that was unfolding, after driving to the first location, I called CQ for the better part of an hour. Then I called some more. When I was done with that, I called CQ more. 90 minutes in, I made my first contact.
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That pretty much set the pattern for the next nine hours. At one point we feared that the radio had packed up, but then I made a 2900 km contact with the other side of the country between me in Perth in VK6 and Catherine VK7GH in Tasmania.
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Around five pm we packed up, having moved location six times, making eight contacts and claiming 64 points, having worked three of the six states I heard.
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Talk about overblown fears.
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Looking back, even documenting 138 contacts on paper doesn't seem nearly as daunting after the fact, but that's for another day. I did learn some other things too.
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I was worried about logging the band correctly, since using a computer that's not connected to the radio requires an extra step when you change band. Using paper the issue wasn't the band, it was remembering to record the time.
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We didn't have the opportunity to test all the gear before the contest. I was bringing in some extra audio splitters, which didn't work with the set-up we had, testing before hand would have revealed that. We knew that there was a risk associated with not testing before and decided that in the scheme of things it didn't matter and we were right. It didn't.
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We hadn't much planned for food and pit-stops, but having a GPS and an internet connection solved all those issues almost invisibly. Of course that wouldn't work in an unpopulated area, but we were well inside the metropolitan area of a big city, well, Perth.
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Using a head-set worked great, though it didn't have a monitoring feature, so my voice got louder and louder and Thomas VK6VCR who took on the tasks of navigating and driving became deafer and deafer as the day progressed.
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I keep coming back to wanting a portable voice-keyer, a device that you can record your CQ call into and then at the press of a button, play it back so you don't lose your voice whilst calling CQ hour after hour. The challenge seems to be that you need to find a way to incorporate it into the existing audio chain so it doesn't introduce interference.
<p>
Winning a contest requires contacts and that can only happen if there are other participants. This time around there didn't seem to be that many on air making noise. I think I heard a grand total of 13 stations. Some of that was due to propagation conditions which were nothing like I've ever heard before, but perhaps if I stick around for another solar cycle, that too will become familiar. Atrocious is one word that comes to mind.
<p>
Continuing our learning, the weather, not just space-weather, actual earth weather, snow, rain, hail and in our case sun. Neither of us thought to bring a hat since the forecast was for intermittent rain. We had no rain, instead had the opportunity to bask in the winter sun. Yes, it's winter here in Oz when it's Summer in Europe. As it happens, our winter temperatures are like your summer ones, but I'll leave it to you to confirm that for yourself.
<p>
Finally, we have a local phenomenon in VK6. When the sun goes down, the 40m band comes alive with the sounds of Indonesia. Among the radio amateurs are plenty of pirate stations with massive AM transmitters enjoying the conditions, chatting, chanting and what ever else comes to voice. Not conductive to being on-air and making noise, but as far as I can tell, not commonly heard outside of VK6.
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That said, the Indonesian radio amateur community must have the patience of saints putting up with the interference that their non-licensed countrymen cause on a daily basis. My hat off to you!
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As I've said all along, this radio thing is about getting on air and having fun and I can tell you, we did.
<p>
What did you get up to?
<p>
I'm Onno VK6FLAB
Listen:
Removing technology for a change
Foundations of Amateur Radio
<p>
My first ever interaction with amateur radio was a field day on Boterhuiseiland near Leiden in the Netherlands when I was about twelve. The station was set-up in an army tent and the setting was Jamboree On The Air, or JOTA. My second field-day, a decade ago, was a visit to a local club set-up in the bush. At that point I already had my licence and I'd just started taking the first baby steps in what so-far has been a decade long journey of discovery into this amazing hobby.
<p>
A field day is really an excuse to build a portable station away from the shack and call CQ. A decade on, I vividly remember one member, Marty, now VK6RC, calling CQ DX and getting responses back from all over the world.
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From that day on I looked for any opportunity to get on air and make noise. Often that's something I do in the form of a contest. I love this as a way of making contacts because each interaction is short and sweet, there's lots of stations playing from all over the planet and each contest has rules and scores. As a result you can compare your activity with others and look back at your previous efforts to see if you improved or not.
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As you've heard me repeatedly say, I like to learn from each activity and see if there are things I could have done differently. I tend to think of this as a cycle of continuous improvement.
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A few months ago a friend asked me if I was interested in doing a contest with him. For me that was a simple question to answer, YES, of course!
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Over the last few months we've been talking about how we'd like to do this and what we'd like to accomplish. For example, for me there's been a regular dissatisfaction that during portable logging I've made mistakes with recording the band correctly in the log and having to manually go back and fix this, taking away from making contacts and having fun. To prevent that, I wanted to make sure that we had electronic logging that was linked to the radio in the same way as I do in my shack, so it didn't happen again. It was a small improvement, but I felt it was important.
<p>
Doing this meant that we'd either need to sort out a computer link, known as CAT, or Computer Assisted Tuning for his radio in the vehicle, or bring my radio, CAT control, power adaptors as well as bring a laptop, power supply and last but not least find space in the vehicle to mount all this so it would work ergonomically for a 24 hour mobile contest. The vehicle in question is the pride and joy of Thomas VK6VCR, a twenty-odd year old Toyota Land Cruiser Ute with two seats, three if you count the middle of the bench, and neither of us would ever be described as petite, so space is strictly limited.
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In playing this out and trying to determine what needed to go where, we discovered that this wasn't going to work and I made the bold proposal to go old school and use a paper log.
<p>
This would mean that we could use the existing radio, without needing to sort out CAT control, the need for any power adaptors, no space required for a laptop, no power for that, no extra wiring in the vehicle, and a whole lot more simplicity. So that's what we're doing, paper log and a headlamp to be able to see in the dark.
<p>
I must confess that I'm apprehensive of this whole caper, but I keep reminding myself that this too is an experience, good or bad, and at the end of the day, we're here to have fun. I might learn that this was the worst idea I've ever had, or I might learn that this works great. It's not the first time I've used a paper-log, so I'm aware of plenty of pitfalls, not the least of which is deciphering my own handwriting, the ingenuous project of three, or was it four, different handwriting systems taught to me by subsequent teachers in different countries. There's the logistics of being able to read and write at an odd distance, trying to work out how to operate the microphone with the wrong hand, though we are trialling a headset and boom microphone with a push to talk button, and then there's the radio, one I've used before, but not in a contest setting and not whilst driving around on the seat of a 4WD hell-bent on rattling my teeth from their sockets.
<p>
On the plus side, I've done a contest with my friend before and he is familiar with my competitive streak and we're both up for a laugh, so I'm confident that despite the challenges that lie ahead, we're going to make fun and enjoy the adventure.
<p>
I can't wait to find out if simplifying things will result in a better experience and only trying it will tell. I'll let you know how it goes.
<p>
When was the last time you stepped out of your comfort zone and what did you do? How did it work out?
<p>
I'm Onno VK6FLAB
Listen:
What radio should I buy as my first one?
Foundations of Amateur Radio
<p>
Recently a budding new amateur asked the question: "What radio should I buy?"
<p>
It's a common question, one I asked a decade ago. Over the years I've made several attempts at answering this innocent introduction into our community and as I've said before, the answer is simple but unhelpful.
<p>
"It depends."
<p>
Rather than explaining the various things it depends on, I'm going to attempt a different approach and in no particular order ask you some things to consider and answer for yourself in your journey towards an answer that is tailored specifically to your situation.
<p>
<p>
"What's your budget?"
<p>
How much money you have set aside for this experiment is a great start. In addition to training and license costs, you'll need to consider things like shipping, import duties and insurance, power leads and a power supply, coax leads and connectors and last but not least, adaptors, antennas and accessories.
<p>
<p>
"Should you buy second hand or pre-loved?"
<p>
If you have electronics experience that you can use to fix a problem with your new to you toy this is absolutely an option. When you're looking around, check the provenance associated with the equipment and avoid something randomly offered online with sketchy photos and limited information. Equipment is expensive. Check for stolen gear and unscrupulous sellers.
<p>
<p>
"What do you want to do?"
<p>
This hobby is vast. You can experiment with activities, locations, modes and propagation to name a few. If you're looking at a specific project, consider the needs for the accompanying equipment like a computer if what you want to explore requires that. You can look for the annual Amateur Radio Survey by Dustin N8RMA to read what others are doing.
<p>
<p>
"What frequencies do you want to play on?"
<p>
If you have lots of outdoor space you'll have many options to build antennas from anything that radiates, but if you're subject to restrictions because of where you live, you'll need to take those into account. You can also operate portable, in a car or on a hill, so you have plenty of options to get away from needing a station at home.
<p>
<p>
"Are there other amateurs around you?"
<p>
If you're within line of sight of other amateurs or a local repeater, then you should consider if you can start there. If that doesn't work, consider using HF or explore space communications. There are online tools to discover repeaters and local amateurs.
<p>
<p>
"Is there a club you can connect to?"
<p>
Amateur radio clubs are scattered far and wide across the planet and it's likely that there's one not too far from you. That said, there are plenty of clubs that interact with their members remotely. Some even offer remote access to the club radio shack using the internet.
<p>
<p>
"Have you looked for communities to connect with?"
<p>
There is plenty of amateur activity across the spectrum of social media, dedicated sites, discussion groups, email lists and chat groups. You can listen to podcasts, watch videos, read eBooks and if all that fails, your local library will have books about the fundamental aspects of our hobby.
<p>
<p>
"Have you considered what you can do before spending money?"
<p>
Figuring out the answers to many of these questions requires that you are somewhat familiar with your own needs. You need a radio to become an amateur, but you need to be an amateur to choose a radio. To get started, you don't need a radio. If you already have a license you can use tools like Echolink with a computer or a mobile phone. If you don't yet have a license, you can listen to online services like WebSDR, KiwiSDR and plenty of others. You can start receiving using a cheap RTL-SDR dongle and some wire.
<p>
<p>
"Which brand should you get?"
<p>
Rob NC0B has been testing radios for longer than I've been an amateur. His Sherwood testing table contains test results for 151 devices. The top three, Icom, Kenwood and Yaesu count for more than half of those results. This means that you'll likely find more information, more support and more local familiarity with those three. I will point out that Rob's list has 27 different brands on it, so look around and read reviews both by people who test the gear and those who use it.
<p>
<p>
And finally, "Why are you here?"
<p>
It's a serious question. Different things draw different people into this community. Think about what you like about it and what you want to do more of. Take those things into consideration when you select your radio.
<p>
<p>
As you explore the answers to these questions, you'll start building a picture of what amateur radio means to you and with that will come the answer to the question: "What radio should I buy as my first one?"
<p>
If there are other questions you'd like to ask, don't hesitate to get in touch. My address is cq@vk6flab.com. I look forward to hearing from you.
<p>
I'm Onno VK6FLAB
Listen:
Bringing chaos into order
Foundations of Amateur Radio
<p>
One of the questions you're faced with when you start your amateur journey is around connectors. You quickly discover that every piece of equipment with an RF socket has a different one fit for purpose for that particular device.
<p>
That purpose includes the frequency range of the device, but also things like water ingress, number of mating cycles, power levels, size, cost and more.
<p>
As an aside, the number of mating cycles, how often you connect and disconnect something is determined by several factors, including the type of connection, manufacturing precision and the thickness of the plating. That said, even a so-called low cycle count connector, like say an SMA connector lasting 500 cycles will work just fine for the next 40 years if you only connect it once a month.
<p>
Back to variety. My PlutoSDR has SMA connectors on it as do my band pass filters, my handheld and one RTL-SDR dongle. The other dongle uses MCX. Both my antenna analyser and UHF antenna have an N-type connector which is the case for my Yaesu radio that also has an extra SO239 which is what my coax switches have. My HF antenna comes into the shack as an F-type and nothing I currently own has BNC, but stuff I've previously played with, does.
<p>
When you go out on a field-day, you mix and match your gear with that of your friends, introducing more connectors and combinations.
<p>
Invariably you acquire a collection of adaptors. At first this might be only a couple, quickly growing to a handful, but after a while you're likely to have dozens or more. My collection, a decade's worth, which currently includes more than 25 different combinations is over a hundred individual adaptors and growing.
<p>
For most of the time these have been tossed into a little tool box with a transparent lid, but more and more as the collection and variety grew I started to realise that I was unable to quickly locate an adaptor that I was sure I had, since it had been used in a different situation previously.
<p>
In addition to coming to the realisation that the reason I couldn't find a connector was because it was still in use, I began to notice that I had daisy chains of connectors.
<p>
For example, my HF antenna has a PL259 connector that is adapted to an F-type connector with an SO239 barrel, a PL259 to BNC and a BNC to F-type adaptor. At the other end of the RG6 coax that runs from outside into the shack, the reverse happens, F-type to BNC and BNC to PL259. If you're counting along, that's five adaptors to get from PL259 to PL259 via F-type.
<p>
At this point you might wonder why I'm using RG6 coax. The short answer is that I have several rolls of it, left over from my days as an installer for broadband satellite internet. RG6 is very low loss, robust and heavily shielded. Although it's 75 Ohm - a whole other discussion - in practice that's not an issue. What is a problem is that the only connectors available for it are F-type compression connectors. To get those to PL259 requires a step sideways via BNC.
<p>
My point is that the number of adaptors is increasing by the day.
<p>
I should acknowledge the existence of so-called universal connector kits. The idea being that you go from one connector to a universal joiner and from that to another connector. Generally these kits have around 30 connections, giving you plenty of options, but in reality more often than not, you only have half a dozen universal joiners, so your money is effectively buying you half a dozen conversions, great for a field day, not so great for a permanent installation. You could build your own collection and use something like SMA or BNC as your universal joiner, which is something I'm exploring.
<p>
To keep track of my collection, recently I started a spreadsheet. It's essentially a list showing the number and types of connections. If you make a pivot table from that you'll end up with a grid showing totals of adaptors you have.
<p>
You can use this grid to fill a set of fishing tackle boxes and all of a sudden you've got a system where everything has its own place.
<p>
If you start this process you'll quickly notice that the table only needs to be half filled, since a BNC to SMA is the same as an SMA to BNC adaptor. This leaves you space to do some fancy footwork where the bottom right hand of the triangle can fit into the top left of the empty space, but I'll leave you to figure that out.
<p>
My table also includes things like TNC and MCX adaptors, but I don't use those very often, so at the moment I'm putting them in their own box together with T-adaptors and other weird and wonderful things like FME and reverse SMA.
<p>
For setting the order, I've gone for alphabetic, but if you have a better suggestion, I'm all ears. My email address as always is cq@vk6flab.com.
<p>
What ideas have you come up with to organise the chaos that is your sprawling connector library?
<p>
I'm Onno VK6FLAB
Listen:
Streaming a dozen repeaters with an RTL-SDR dongle
Foundations of Amateur Radio
<p>
A while ago as part of my ongoing exploration into all things radio I came across a utility called rtlsdr-airband. It's a tool that uses a cheap software defined radio dongle to listen to a station frequency or channel and send it to a variety of different outputs. Originally written by Tony Wong in 2014, it's since been updated and is now maintained by Tomasz Lemiech. There are contributions by a dozen other developers.
<p>
The original examples are based around listening to Air Traffic Control channels. I know of a local amateur who uses it to listen to and share the local emergency services communication channels, especially important during local bush fires.
<p>
While sophisticated, it's a pretty simple tool to use, runs on a Raspberry Pi, or in my case, inside a Docker container. It's well documented, has instructions on how to compile it and how to configure it.
<p>
Before I get into what I've done, as a test, let's have a look at the kinds of things that rtlsdr-airband can do.
<p>
First of all, it's intended to be used for AM, but if you read the fine documentation, you'll learn that you can also make it support Narrowband FM. It can generate output in a variety of different ways, from a normal audio file, to an I/Q file - more about that at another time, and it can also send audio as a stream to a service like icecast, broadcastify or even to your local pulse audio server. If that last one doesn't mean much to you, it's a local network audio service, popular under Linux, but it runs on pretty much anything else thanks to the community efforts of many.
<p>
So, on the face of it, you can listen to a channel, be it AM or Narrowband FM, and send that to some output, but I wouldn't spend anywhere as much time on this if that was all there was to it.
<p>
The software can also dynamically change channels, support multiple dongles, or simultaneously listen to several channels at once and output each of those where ever you desire.
<p>
Another interesting thing and ultimately the reason I thought to discuss it here is that rtlsdr-airband also supports the concept of a mixer. You can send multiple channels to a single mixer and output the result somewhere else.
<p>
Using a mixer, in addition to setting cut off frequencies and other audio attributes, you can set the audio balance for each individual channel. This means that you can mix a channel exclusively to the left ear, or to the right ear, to both, or somewhere in between.
<p>
Now, to add one extra little bit of information.
<p>
In my location there's about a dozen or so amateur repeaters most of which can be heard at some time or another from my QTH. The frequency spread of those dozen repeaters is less than 2 MHz. A cheap RTL-SDR dongle can handle about 2.56 MHz.
<p>
Perhaps you've not yet had the ah-ha moment, but what if you were to define an rtlsdr-airband receiver that listened to a dozen amateur radio repeaters - at the same time - and using the audio balance spread those repeaters between your left and right ear, you could stream that somewhere and listen to it.
<p>
I'm sitting here with my headphones on, listening to the various repeaters do their idents, various discussions on different repeaters, a local beacon, incoming AllStar and other links, all spread out across my audio horizon, almost as if you can see where they are on the escarpment, though truth be told, I've just spaced them out evenly, but you get the idea.
<p>
My original Raspberry Pi wasn't quite powerful enough to do this in the brute force way I've configured this, so as a proof of concept I'm running it on my main computer, but there's nothing to suggest that doing a little diligent tweaking won't make my Pi more than enough to make this happen.
<p>
As for audio bandwidth, it's a single audio stream, so a dial-up connection to the internet should be sufficient to get the audio out to the world.
<p>
I will point out that there may be legal implications with streaming your local amateur repeaters to the world, so don't do that without checking.
<p>
For my efforts, this is an example of: "I wonder if ..."
<p>
As it turns out, Yes you can. As it happens, my next challenge is to use this code on a PlutoSDR where the bandwidth is slightly larger, mind you, I'll have to do some fancy footwork to process the data without overwhelming the CPU, but that's another experiment in my future.
<p>
What kind of crazy stuff have you tried that worked?
<p>
I'm Onno VK6FLAB
Listen:
Soldering Irons and Software
Foundations of Amateur Radio
<p>
The activity of amateur radio revolves around experimentation. For over a century the amateur community has designed, sourced, scrounged and built experiments. Big or small, working or not, each of these is an expression of creativity, problem solving and experimentation.
<p>
For most of the century that activity was accompanied by the heady smell of solder smoke. It still makes an appearance in many shacks and field stations today, even my own, coaxed by an unsteady hand, more and more light and bigger and bigger magnification, I manage to join bits of wire, attach components and attempt to keep my fingers from getting burnt and solder from landing on the floor.
<p>
I've been soldering since I was nine or so. I think it started with a Morse key, a battery and a bicycle light with a wire running between my bedroom and the bedroom of my next door neighbour. In the decades since I've slightly improved my skill, but I have to confess, soldering isn't really my thing.
<p>
My thing is computers. It was computers from the day I was introduced in 1983 and nothing much has changed. For reasons I don't yet grasp, I just get what computers are about. They're user friendly, just picky whom they make friends with.
<p>
When I joined the amateur community, it was to discover a hobby that was vast beyond my wildest imagination, technical beyond my understanding and it was not computing. Little did I know.
<p>
Computing in amateur radio isn't a new thing. For example, packet radio was being experimented with in 1978 by members of the Montreal Amateur Radio Club, after having been granted permission by the Canadian government. In 2010 when I came along we had logging, DX-clusters and the first weak signal modes were already almost a decade old.
<p>
Software Defined Radio has an even longer history. The first "digital receiver" came along in 1970 and the first software transceiver was implemented in 1988. The term "software defined radio" itself was 15 years old when I joined the hobby and truth be told, it's a fascinating tale, I'll take a look at that at another time.
<p>
When I started my amateur journey like every new licensee, I jumped in the deep end and kept swimming. From buying a radio, to discovering and building antennas, from going mobile to doing contests and putting together my home station, all of it done, one step at a time, one progressive experiment after another, significant to me, but hardly world shattering in the scheme of things.
<p>
Now that I've been here for a decade I've come to see that my current experiments, mostly software based, are in exactly the same spirit as the circuit builders and scroungers, except that I'm doing this by flipping bits, changing configurations, writing software and solving problems that bear no relation to selecting the correct combination of capacitance and reactance to insert into a circuit just so.
<p>
Instead I'm wrestling with compilers, designing virtual machines, sending packets, debugging serial ports and finding new and innovative ways to excite transceivers.
<p>
For example, today I spent most of the day attempting to discover why when I generate a WSPR signal in one program, it cannot be decoded by another. If that sounds familiar, that was what I was doing last week too. This time I went back to basics and found tools inside the source code of WSJT-X and started experimenting. I'm still digging.
<p>
As an aside I was asked recently why I want to do this with audio files and the short answer is: Little Steps.
<p>
I can play an audio file through my Yaesu FT-857d. I can receive that and decode it. That's where I want to start with my PlutoSDR experiments, so when I'm doing this, I can use the same audio file and know that the information can be decoded and that any failure to do so is related to how I'm transmitting it.
<p>
Back to soldering irons and software. In my experience as an amateur it's becoming increasingly clear that they're both the same thing, tools for experimentation, with or without burning your fingers.
<p>
I'm Onno VK6FLAB
Listen:
Getting started on WSPR with a PlutoSDR
Foundations of Amateur Radio
<p>
As you might recall, I took delivery of a device called a PlutoSDR some time ago. If you're not familiar, it's a single-board computer that has the ability to transmit and receive between 70 MHz and 6 GHz. The system is intended as a learning platform, it's open source, you get access to the firmware, compilers and a whole load of other interesting tools. I used it to play with aviation receive using a tool called dump1090 which I updated to use Open Street Map. If you're interested, it's on my VK6FLAB github page.
<p>
Over the past few months I've been steadily acquiring little bits and pieces which today added up to a new project.
<p>
Can I use my PlutoSDR to transmit WSPR?
<p>
This all started because of an experiment and a conversation.
<p>
The experiment was: "Using my FT-857d on 70cm can I transmit a weak signal mode like WSPR and have my friend on the other side of the city decode the transmission?" The answer to that was a qualified "Yes". I say qualified, since we weren't able to transmit a WSPR message, but using FT8 we were happily getting decodes across the city. We're not yet sure what the cause of this difference is, other than the possibility that the combined frequency instability at both ends was large enough to cause an issue for a WSPR message, which lasts about two minutes. On the other hand, I learned that my radio can in fact go down to 2 Watts on 70cm. I've owned that radio for over a decade, never knew.
<p>
Now that I have a band pass filter, some SMA leads and the ability to talk to my Pluto across the Wi-Fi network, I can resurrect my Pluto adventures and start experimenting.
<p>
I mentioned that this was the result of an experiment and a conversation.
<p>
The conversation was about how to create a WSPR signal in the first place. At the moment if you run WSJT-X the software will generate audio that gets transmitted via a radio. All fine, except if you don't have a screen or a mouse. Interestingly a WSPR transmission doesn't contain any time information. It is an encoded signal, containing your callsign, a maidenhead locator - that's a four or six character code representing a grid square on Earth, and a power level. That message doesn't change every time your transmitter starts the cycle, so if you were to create say an audio file with that information in it, you could just play the audio to the nearest transmitter, like a handheld radio, or in my case a Pluto, and as long as you started it at the right time, the decoding station wouldn't know the difference.
<p>
As an aside, if you're playing along with your own Pluto, and far be it for me to tell you to go and get one, you can set the Pluto up using either USB, in which case it's tethered to your computer, or you can get yourself a USB to Ethernet adaptor and connect to it via your network. If you have a spare Wi-Fi client lying around, you can get that to connect to your Wi-Fi network, connect the Pluto via Ethernet to the Wi-Fi client and your gadget is connected wirelessly to your network. I can tell you that this works, I'm typing commands on the Pluto as we speak.
<p>
As is the case in any experiment in amateur radio, you start with one thing and work your way through. At the moment I want to make this as simple as possible. By that I mean, as few moving parts as I can get away with. I could right now fire up some or other SDR tool like say GNU Radio and get it to do the work and make the transmission, but what I'd really like to do is actually have the Pluto do all the work, so I'm starting small.
<p>
Step One is to create an audio file that I can transmit using the Pluto.
<p>
It turns out that Step One isn't quite as simple as I'd hoped. I located a tool that actually purports to generate an audio file, but the file that it builds cannot be decoded, so there's still some work to be done.
<p>
On the face of it the level of progress is low, but then this whole thing has been going for months. The experiment on 70cm lasted half an hour, the discussion took all of a cup of coffee. So far, I've spent more time on this project making the Wi-Fi client talk to my network than all the rest put together and that includes finding and ordering the Pluto in the first place.
<p>
You might well wonder why I'm even bothering to talk about this as yet unfinished project. The reason is simple. Every day is a new one. Experiments are what make this hobby what it is and every little thing you learn adds to the next thing you do. Some days you make lots of progress, other days you learn another way to not make a light bulb.
<p>
I'm Onno VK6FLAB
Listen:
Ergonomics in your shack
Foundations of Amateur Radio
<p>
In my day job I work in computing. For many years that consisted of going on-site and fixing stuff. Invariably this involved me fixing servers that were installed into a room the size of a broom closet with an optional air conditioner screaming in my ear. The experience often included sitting on a crate, or the floor, holding a keyboard and if it was a Windows Server, rolling a mouse on my knee in order to click on stuff barely discernible on a tiny screen that likely sat a meter too high above my eye line with Ethernet wires going diagonally from one end of the room to the other.
<p>
These days with ubiquitous internet connectivity that kind of experience is mostly a thing of the past.
<p>
That said, operating a radio during a contest in many stations I've used over the years is not far from that kind of layout.
<p>
Often a traditional shack starts off with a radio on a table with a notepad to record contacts. Over time that gets expanded with technology like a computer. It's common to have to juggle the radio display and keyboard, to find a spot for the mouse that doesn't interfere with the desk microphone, or to have to reach over to change band and to activate a different filter, select another antenna, use the rotator or some other essential tool that's required for making that elusive contact.
<p>
Some stations have multiple monitors, sometimes they're even together, but more often than not they're a different size, sitting too high and the radio sits as a road-block between your eye line between the screen and the keyboard.
<p>
I'm raising this because over the years I've not actually seen anyone spend any energy on discussing how you might improve this experience.
<p>
If this was your workplace, the occupational health and safety police would be all over you and for good reason. You could argue that amateur radio is a hobby and that OH&S is of lesser concern, but to that I'd like to point out that you have the same risk of self injury at work as you do in your shack, especially if you're doing a contest for 24 or 48 hours.
<p>
Not only is there a risk of injury, why make the experience harder than it needs to be? Ergonomics is the process of designing or arranging a workplace to fit the user. It's a deliberate process. You have to actually stop to consider how you are using a space, in this case your shack.
<p>
At the moment I'm experimenting with different aspects of the layout of my shack. For example, I started with a layout of the computer, counter intuitive perhaps, since we're talking about a radio shack, but given that I'm spending much of my time doing contests and digital modes, the computer is used much more than the radio is, even if the radio is what's making all the on-air noise.
<p>
After making sure that my keyboard, mouse and screen were in locations that actually helped me, I started trying to figure out where to put the radio and what role it actually plays in making the contact. If during a contest you're using search and pounce, which is when you hunt up and down the bands looking for a contact, you might argue that you'll need access to the radio to change frequency, but if you already have your computer connected to the radio, you can change frequency from the keyboard or by control with your mouse.
<p>
Another way I'm looking on reducing the amount of stress to my body whilst operating my station is by sorting out audio. Almost every radio has a speaker on it, but if you've got more than one going at the same time it becomes really difficult to determine which one is actually making noise and even harder if multiple stations are on different frequencies on different radios at the same time.
<p>
You could wear headphones and select a radio, one at a time, either by plugging in a particular radio, or by using a selector. If you're using digital modes, the audio might already be going into the computer, which offers you the ability to select from different sound cards, but there are other options. I'm working on plugging the audio from each radio into an audio mixer that will allow me to set the level for each radio independently, mute at will, set the tone, the balance between left and right ear and a few other things.
<p>
For a microphone I plan on using the same mixer and I'm working on how to have my digital audio coming from the computer incorporated into the same audio environment, because the digital audio could just as easily be a voice caller using the same system.
<p>
For push to talk I settled on a foot switch a couple of years ago. That said, if I'm on my own, I tend to use VOX, or voice operated switching, which turns on the transmitter when microphone audio is detected by the radio. This will need some careful planning if I'm going to connect multiple radios, since I don't want to transmit the same message across each radio at the same time, but with computer control, that too can be addressed.
<p>
My point is that we have lots of technology available to us as radio amateurs to achieve what ever we need to. It takes extra effort to decide how you might go about making your environment a place where you can safely sit and operate without making life harder than it needs to be.
<p>
What kinds of different techniques and technologies have you used to make your shack a more comfortable environment? Do you spend your days hunting DX, doing contests or making digital contacts, or something else? Have you considered how you might improve the layout of your shack to suit your particular use-case and when was the last time you checked to see if the decisions you originally made are still valid today?
<p>
I'm Onno VK6FLAB
Listen:
How much bandwidth is there?
Foundations of Amateur Radio
<p>
Have you ever taken a moment to consider the available bandwidth on the various amateur bands?
<p>
As an entrant into amateur radio in Australia as a Foundation licence holder you have access to six different amateur bands, the 80m band, 40m, 15m, 10m, 2m and 70cm. If you add the bandwidth from each of those bands together, you end up with 26.65 MHz worth of bandwidth to play with in Australia.
<p>
I can tell you that's a big chunk of bandwidth, but until I give you some context, 26.65 MHz isn't likely something that you can picture.
<p>
You might think of things as being pretty crowded. For example, on the 40m band during a contest it's common to hear wall to wall signals. There's barely enough room to call CQ and not interfere with anyone else. But how crowded is it really?
<p>
Let's start with an SSB signal, typically it's 2.4 kHz wide. On the 40m band, with 300 kHz of bandwidth, there's room for about 125 SSB signals side-by-side. On the 10m band, there's space for over 700 SSB signals side-by-side. Across all the available bandwidth for a Foundation license holder in Australia, there's room for over 11-thousand different SSB signals side-by-side.
<p>
While we're on the subject of crowding, there's talk about the massive influx of FT8, some call it a scourge. FT8 channels are transmitted within a single SSB channel and each takes up 50 Hz. That means that within an SSB channel of 2.4 kHz, there's room for 48 different FT8 channels, and if you take into account the odd and even time-slots, that doubles to 96 different signals, all within the same single SSB channel. So while FT8 is popular and growing, let's not get too excited about how much space it's taking up. From the perspective of an Australian Foundation license holder, it's taking up exactly six separate SSB slots of those 11-thousand across the six available bands, room for 576 separate FT8 signals, taking up a total of 14.4 kHz, or 0.05% of the available bandwidth.
<p>
Let's look at this another way, of the 26.65 MHz available bandwidth, 20 MHz is from the 70cm band alone, that means that all the other bands put together, fit inside the 70cm band three times over.
<p>
Let that sink in for a moment, adding the 80m, 40m, 15m, 10m and 2m band together fit inside the 70cm band three times.
<p>
You can use the 70cm band alone for 800-thousand FT8 signals, remember that there's two time slots, so you get two for one.
<p>
If this makes your mind explode, then consider that a carrier wave signal is considered to be about 25 Hz wide, so on the 70cm band you could have 800-thousand individual CW signals. You could allocate a personal CW frequency to every one of the amateurs in the United States in the 70cm band and still have room for expansion, not that I'm advocating that, just to give you a sense of scale. I should note that the 70cm band in the United States is even larger than it is in Australia, but I don't want to get bogged down into the various band plans across the world at the moment.
<p>
You might ask yourself why am I getting so excited about this?
<p>
Amateur radio is about experimentation. I've been telling you about HF propagation and using techniques like FT8 to determine just how far your signal goes, but you could use the same techniques to build a 70cm communication network with the amateurs within your city and share information across the city, perhaps even build a mesh network using your 70cm hand-held and an FT8-call network. It could be used to distribute propagation information, or messages in case of an emergency, or form the basis of something completely different.
<p>
If that doesn't whet your appetite, consider that the 1mm amateur band, which runs from 241 to 250 GHz is ready for you to experiment when your license permits. The current world distance record is 114 km, set in 2008 by Brian WA1ZMS and Peter W4WWQ, it has 9 GHz bandwidth and has room for 360-million FT8 signals, or 60 exclusive FT8 channels for every amateur on the planet.
<p>
My point is that as radio amateurs we have access to a massive chunk of radio bandwidth and it's just sitting there waiting for you to experiment with.
<p>
I'm Onno VK6FLAB
Listen:
The massive physics phenomenon just over eight minutes away ...
Foundations of Amateur Radio
<p>
If you've been around radio amateurs for a little while you're likely to have heard about the Solar Cycle and that it affects radio propagation for HF or High Frequency, also known as shortwave communications. The frequencies in the range of around 3 to 30 MHz, or 100m to 10m wavelength. One of the main ways it's used is for is for long distance or global communication and one of the most common ways that's done is using the ionosphere around the globe to refract a radio signal.
<p>
In September 2020, the Solar Cycle 25 Prediction Panel, announced that Solar Cycle 25 had commenced in December 2019 and radio amateurs around the globe rejoiced.
<p>
The first question for me was, why Solar Cycle 25?
<p>
You might think of the Sun as a stable light in the sky. As it happens, the bright light hides all manner of ferocious activity. One of the measures of this activity is the number of dots observed on the surface of our Star. These dots are called sunspots. As Solar activity increases, the number of sunspots increases. The activity is cyclical, it increases and decreases over time. Each increase and decrease combined is known as a Solar Cycle.
<p>
On average a cycle lasts about 10.7 years. Simple maths gives you that Solar Cycles started somewhere around 1750. That seems a little strange. Our Sun is 4.6 billion years old. There are paintings on the rocks at Ubirr in the Northern Territory of Australia that are 40 thousand years old. The pyramids in Egypt are 45 hundred years old. The Solar Cycle has been going for a lot longer than the 7 million years there have been humans on the planet, let alone dinosaurs who experienced the Solar Cycle 66 million years ago. Using fossil records we've determined that the Solar Cycle has been stable for at least the last 700 million years.
<p>
Chinese astronomers recorded Solar activity around 800 BC and Chinese and Korean astronomers frequently observed sunspots but no known drawings exist of these observations. The first person to draw sunspots was John of Worcester on the 8th of December 1128. Five days later, half a world away in Korea on the 13th of December 1128, the astronomers in Songdo reported a red vapour that "soared and filled the sky", describing the aurora borealis in the night sky that resulted from those very same sunspots.
<p>
In the early 1600's there was plenty of activity around the recording of sunspots. Thomas Harriot appears to have predated Galileo Galilei by more than a year with notes and drawings dated the 8th of December 1610. There's plenty of other names during this period, Father and son David and Johannes Fabricius and Christoph Scheiner to name three, but I'm moving on.
<p>
The Solar Cycle, was first described by Christian Horrebow who more than a century later in 1775 wrote: "it appears that after the course of a certain number of years, the appearance of the Sun repeats itself with respect to the number and size of the spots". Recognition of the Solar Cycle was awarded to Samuel Heinrich Schwabe who noticed the regular variation in the number of sunspots and published his findings in a short article entitled "Solar Observations during 1843" in which he suggested that the cycle was 10 years.
<p>
Stay with me, we're getting close to Solar Cycle number One.
<p>
In 1848 Rudolf Wolf devised a way to quantify sunspot activity. His method, named the Wolf number, is still in use today, though we call it the relative or international sunspot number. In 1852 he published his findings on all the available data on sunspot activity going back to 1610 and calculated the average Solar Cycle duration as 11.11 years. He didn't have enough observations to reliably identify Solar Cycles before 1755, so the 1755-1766 Solar Cycle is what we now consider Solar Cycle number One lasting 11.3 years with a maximum of 144.1 sunspots in June of 1761.
<p>
Until 2009 it was thought that there had been 28 Solar Cycles between 1699 and 2008 with an average duration of 11.04 years, but it appears that the 15 year Solar Cycle between 1784 and 1799 was actually two cycles, making the average length only 10.7 years. I should also point out that there have been Solar Cycles as short as 8 years and as long as 14 years.
<p>
With the announcement of Solar Cycle 25 comes improved propagation for anyone who cares to get on air and make noise. The current predictions vary depending on the method used, ranging from a very weak to a moderate Solar Cycle 25. There are predictions for the Solar maximum, the time with the most sunspot activity, to occur between 2023 and 2026 with a sunspot range between 95 and 130. By comparison during the previous Solar Cycle, in 2011 the first peak hit 99 and the second peak in 2014 hit 101.
<p>
I have purposely stayed away from electromagnetic fields, geomagnetic impacts and the actual methods for HF propagation, I'll look at those another time.
<p>
I can tell you that we've gone a little beyond counting dots on the Sun to determine activity and we have a whole slew of satellites orbiting our Star doing all manner of scientific discovery, all of which helps our understanding of what's going on in the massive physics phenomenon 8 minutes and 20 seconds away by radio.
<p>
That said, Solar eruptions are still pretty unpredictable, much like the weather around us. Not because we don't want to know, but because this is a very complex one to solve, much like ionospheric propagation is hard to forecast, much easier to measure actual performance and much more accurate.
<p>
So, if you want to know how well propagation is going to be today, turn on your radio and have a listen. If you want to know how great it's going to be tomorrow, look at the forecast, but bring an umbrella, or an FT8 transmitter.
<p>
I'm Onno VK6FLAB.
Listen:
The dynamic nature of your shack
Foundations of Amateur Radio
<p>
If you have the opportunity to build your shack, it might start off as a table in the corner where you plonk down a radio, plug into nearby power and run coax to. That's pretty much how most shacks start, mine included.
<p>
For me the step of running coax was an activity that took weeks of planning and procrastination and days of climbing on the roof. After actually completing that and getting two runs of coax to my planned shack, one for HF and one for UHF and VHF, the shack building itself was pretty simple.
<p>
I had to get power to the location, but an extension lead took care of that. In the interest of space I put the power supply on the floor, a wooden floor that ensured good circulation, unlike carpet, perhaps a topic for another day, I plugged my coax into the radio, plugged in the 12 Volt power and was up and running.
<p>
Over time that space continued to grow. Looking at it right now, it has two computer monitors, a laptop, three radios, two coax switches, a keyboard, mouse, digital interface, two speakers, and a fan to cool the radio when I'm calling CQ on FT8.
<p>
I'm not a messy person, but I do like to have my tools convenient. It's not a pristine environment by any stretch, but it's orderly as shacks go. An hour ago it wasn't, actually, looking at the clock, that was four hours ago. Time flies when you're having fun.
<p>
My shack is the centre of my radio activities. I might receive a gadget from a friend to test and I'll put it on my desk ready to go. The same is true for a foot pedal that I found when looking for something else, as is the audio adaptor that I used in the desk mixer that I'm experimenting with.
<p>
Over time each of these bits and pieces accumulate on the surface.
<p>
When I noticed that my radio was running hot, or in my mind uncomfortably warm, given that I'm using 5 Watts, I decided to invest in a fan, clipped to the edge of the desk requiring yet another wire.
<p>
It's not limited to small bits. I'm testing a new radio, that comes with removable head, a microphone, cables to join those to the main body, two antenna port cables, a coax switch and a power lead with two cables.
<p>
Over time you have coax mixed with 12 Volt DC and 240 Volt AC, audio leads, USB leads, video leads, grounding wire, remote control switches, microphone leads, CAT leads and more, all running all over the place.
<p>
Making a minor change can become a big hassle, making it hard to determine what goes where, not to mention that each cable generates it's own little slice of RF, wanted or not.
<p>
The four hours I've just spent consisted of taking everything except the bolted on computer monitors off the desk and starting from scratch.
<p>
I also did this when I first added a second radio, but that was so long ago that the "system" I implemented then was unrecognisable. Doing it again today I made better use of the environment and changed some things around. I started with the 240 Volts requirements, then the coax, then 12 Volts, then audio and finally USB, using cable ties for semi-permanent things like power boards and hook and loop straps for things that move more frequently like audio wiring and video cables.
<p>
It's not perfect. I'm looking for some flexible coax patch leads, there's USB cables going every which way, the laptop keyboard isn't used, so why use a laptop, no doubt I'll discover more.
<p>
My point is that this is dynamic and every now and then it pays to spend a little while putting things back together.
<p>
My next project is to use an audio mixer to bring all the audio together in one place so I can use one headset for everything and give me the opportunity to plug in a tape recorder as my regulator suggests for monitoring emergency communications, though I might have to come up with something a little less 1980 for the actual recording.
<p>
If you're going to do this, move the desk at least a meter from the wall so you can get at the back of your shack, you can thank me later.
<p>
I'm Onno VK6FLAB
Listen:
When you just have to try things ...
Foundations of Amateur Radio
<p>
A little while ago I was gifted a new radio, well, new to me. A Kenwood TS-480HX. It's an all mode HF transceiver with 6m. Does 200 Watts, but you know me, I'm into QRP, low power, so I first had to figure out how to dial the transmitter down to 5 Watts and that was after figuring out how to feed the dual power supplies from one source and have the fuses work as expected.
<p>
When I received the radio, I took stock of all the bits that it was packed with, all complete, all the accessories, even the user manual was laminated. The previous owner, Walter VK6BCP (SK) whom I never met was an amateur after my own heart. I've talked about how he meticulously documented his alterations to a power supply for example.
<p>
Previously I've taken this radio on holidays to operate portable in a field day. The experience was underwhelming, in that I didn't hear anyone and nobody responded to my CQ calls. At the time I put it down to a poor antenna and unfamiliarity with the radio, despite reading the manual, well, at least scanning it.
<p>
Today I finally set some time aside to do some more testing. I decided that the first step would be to actually set it up in my shack, next to my trusty Yaesu FT-857d and see how it performs in comparison.
<p>
So, I plugged everything in, found a coax switch so I could switch the antenna between the two radios and learned that the audio connector that I've been using for digital modes on the Yaesu is actually compatible with the Kenwood. Now I need to make another adaptor for this radio, but in the meantime I can move the audio plug between radios when I swap.
<p>
In doing this I learnt a few things.
<p>
One is that there's plenty of scope for things to break.
<p>
For example, I was reaching over the desk to plug a connector into the coax switch when I leaned on the keyboard and touched the space bar. This caused the radio that I was working on to start its tuning cycle without an antenna connected. Fortunately I was using 5 Watts and I caught it within seconds, so no white smoke this time around.
<p>
It does remind me to turn off the radio when fiddling with connectors though. I'm embarrassed to report that I thought I'd learnt that lesson already, nothing like a refresher course in transmitter safety and dumb things not to do in the shack.
<p>
Then there was the thing about using remote control. In my naivety I thought that the connector that the Yaesu uses for computer control is also used on the Kenwood. Turns out that it isn't. Fortunately I read the manual before plugging that in.
<p>
The Yaesu has a specific digital mode with individual gain and filter characteristics, which seem to be completely lacking on the Kenwood.
<p>
I'm still attempting to learn the differences in receive performance between the two. I started this process by running WSJT-X and listening to WSPR or Weak Signal Propagation Reports and testing how both radios decode things. I cannot yet do this side-by-side, but for now I can swap and see signals coming in on either radio.
<p>
This is not the first time I've put a different radio on my desk to see how it works and it's not going to be the last time. What I'm looking to achieve is to swap over from the Yaesu to the Kenwood in my shack, so I can put the Yaesu back in the car and have a mobile shack operating again because I have to admit, I do miss that.
<p>
What kinds of testing regimes to you have when you're trying out a new radio? I'd love to hear your thoughts. My email address as always is cq@vk6flab.com.
<p>
I'm Onno VK6FLAB
Listen:
Portable experiences ...
Foundations of Amateur Radio
<p>
Last weekend was memorable for all the right reasons. Filled with 24 hours of amateur radio, spent with friends, in a park, making noise and having fun, marking the first time I recall setting up in a park for that length of time with so few extra resources. Normally we'd be decked out with tents, or in my case a swag, we'd have camping stoves, perhaps even a caravan or two, tables, cutlery, the whole shebang.
<p>
This time we brought none of that. Just radios, antennas, batteries, water with a few snacks and folding chairs.
<p>
This was like nothing I've experienced before and it has me asking myself: Why did I wait so long to operate like this?
<p>
It was wonderful.
<p>
We spent it being on-air and making noise during a 24 hour contest which is specifically intended to celebrate and reward portable operation. In case you're wondering, the John Moyle Memorial Field Day is to encourage portable field day operation and provide training for emergency situations. It was created in memory of John Moyle, the long term editor of Wireless Weekly, who served in the RAAF with distinction. He's said to be responsible for a number of innovative solutions to keeping radio and radar equipment working under difficult wartime conditions.
<p>
I've participated in this contest plenty of times before. This was the first time I did it in a park, in the city, and as experiences went it was fabulous and recommended.
<p>
As you might know, I like operating portable. I've been operating from my car for years, from camp-sites in remote locations for just as long and I've activated several parks and peaks in Summits On The Air, or SOTA, and World Wide Flora and Fauna, or WWFF activities. I've also set-up during field days in local parks and I regularly drive to a local park to get on-air and make noise. With that as background, you might ask yourself, what is different?
<p>
Let's start with setting the scene.
<p>
The park that we used is located in a suburb about 10 km out from the city centre. It has a river running through it and on the banks there are plenty of trees with lawn. Dotted throughout are picnic tables with wooden gazebos. All very civilised.
<p>
From a radio perspective, it was RF quiet, that is, no local electrical noise, away from cars, from a footpath, close enough to parking where we could get our gear out of the car and walk it to the site.
<p>
All that alone would have made for a great experience, but this went beyond that.
<p>
For example, dinner consisted of ordering from the local fish and chips shop five minutes away and picking up some amazing seafood. While there collecting some extra water and most importantly dessert from the supermarket next door.
<p>
During our activities we had visits from local amateurs. Over the 24 hours we had a steady stream of interested hams coming out and having a chat. Some took the opportunity to bring food, dips and crackers, thermos flasks of tea, even ice cold beer. One amateur came along at the end of our activation and helped pack-up. All this made for a very enjoyable social experience.
<p>
Another thing that was different was that the operator could wear headphones without stopping anyone else from hearing what was going on. We achieved that by connecting a headphone splitter to the radio, piping the audio to some external speakers for local monitoring whilst the operator wearing headphones would not be affected by conversations taking place around them.
<p>
We did have some challenges.
<p>
Our logging tool of choice was, for reasons we don't yet understand, switching bands which meant that sometimes the numbers we were giving out were not sequential. Generally in a contest situation you exchange a piece of information in addition to a signal report. In this case it's supposed to be a sequential number and because there were multiple operators, the sequence is supposed to be per band.
<p>
The trees provided shade, but were not quite up to the task of being sky-hooks able to hold up wire antennas, fortunately we brought squid poles for that purpose.
<p>
It was hot. 38 degrees Celsius. It turns out that even though wearing a black long-sleeve T-shirt is not a suitable fashion choice from a temperature perspective, it was perfect in preventing sunburn and for that I was immensely grateful.
<p>
As you might know, we track what we bring in a spreadsheet, one row per item. A column for each time we go out. Over time we learn what's used and what's not. Our list is getting better and better.
<p>
I'll admit that I felt some trepidation in relation to this location, but I'm so glad that I took a leap of faith and went with the experience.
<p>
What a blast!
<p>
What kind of activities have you been up to that gave you a blast?
<p>
I'm Onno VK6FLAB
Listen:
The remote edge...
Foundations of Amateur Radio
<p>
The landscape of remotely operated amateur radio is changing by the day. Once the territory of home brew DTMF decoders and remote controlled radio links, now more often than not it's a Raspberry Pi with an internet connection, or some variation on that.
<p>
Before I continue, I must point out that amateur regulations vary widely around the globe, especially in this area. It appears mostly due to the rapidly changing nature of remotely operated radios.
<p>
For example, most, if not all software defined radios are technically remotely operated. You run software on your computer, the radio is connected to a network, you twiddle a setting on your computer and the radio responds. The computer is not part of the radio, but without it there's not much radio to be had. There's no need for both to be in the same room, let alone the same building.
<p>
Similarly, a Kenwood TS-480 and a Yaesu FT-857d are both radios that have a removable face with knobs and a display. The main body of the radio is a nondescript box with sockets for power and antenna, connected to the face essentially via a serial cable that can be a few centimetres long, or a few meters. There's solutions like RemoteRig that replace this serial cable with a virtual cable, allowing you to put the face in one location and the body in a different one, connected to each other across the internet.
<p>
With the introduction of Starlink internet, a low earth orbit satellite based network, a connection to the internet can be made anywhere on earth, making it possible to have your station sitting somewhere far away from interference, powered by batteries and solar panels and connected to the internet. You might not even need to go to satellite based internet, the mobile phone network in many places is often more than sufficient for making such a station viable.
<p>
If you're a member of a radio club, you might consider your club station. Often this station is the work of many volunteer years effort with multiple radios, antennas, filters and the like and often it sits idle most of the time, only getting fired up during club meetings or the weekend. What if you connected that station to the internet and offered it as a service to your members?
<p>
Depending on license requirements, you might consider amateurs who have limited ability to build a shack but would love to be on air making noise. A remote club shack might be just the ticket for getting them on air. It could even become an income stream for your club.
<p>
You might be able to offer access to trainees, or let them monitor the station without transmit ability whilst they're preparing for their license, or you might operate a 48 hour contest in shifts, all using the same transmitter, but from the comfort of your home.
<p>
The landscape is full of different solutions, like RemoteRig, which I've already mentioned, RigPi Remote Station Server is a tiny computer that controls your radio and allows you access via a web browser or remote desktop connection. There's Remote Hams, a ready made solution for putting your shack on air with access control and remote management. You can connect specific radios, like the Elecraft K3 Remote System, or a Flex Radio Maestro, there's even web browser remote control projects like Universal Ham Radio Remote by Oliver F4HTB, each making it possible to get on air and make noise using a radio in a different location across the internet.
<p>
All of the solutions I've named make it possible to fully use your radio, that means CW, SSB, FM, antenna control and the like. You can use it for FT8 or RTTY, the choice is yours.
<p>
The interface might be the face of your radio, a special console, computer, phone or a tablet and you can operate it wherever and whenever the mood takes you.
<p>
No longer do you need to have a shack in your home with coax snaking through the walls to an antenna whilst dodging the local authorities, or fighting the engine noise from your car. You can make the ultimate shack anywhere without taking up space in your home or car.
<p>
One final comment. This is a moving feast. The level of functionality is increasing by the day. For me this journey started with a steel toolbox in my garage with a radio inside it and coax running from the box to my antenna. I have operated my radio and hosted my weekly net like this. The radio in the garage, me in my office connected via Wi-Fi over a virtual serial cable. You don't need to start this in the middle of nowhere, six hours drive over the back roads to fix a problem, you can start this project today at home.
<p>
Where on this journey are you and what issues have you come up against? Let me know. My address as always is cq@vk6flab.com
<p>
I'm Onno VK6FLAB
Listen:
Making observations
Foundations of Amateur Radio
<p>
Amateur radio is an environment for infinite possibilities. I've spoken about the way that contacts can happen, seemingly out of the blue, how propagation has so many variables it's hard to predict what will happen at any given moment. During a contest you might scan up and down the bands looking for an elusive multiplier, a contact that's worth extra points, or a missing DXCC country, in your quest to contact a hundred or more. It's easy to get swept away in the excitement and disappointment that comes with success and failure.
<p>
I'm mentioning this because it's pretty much how many people in our community go about their hobby, me included.
<p>
I've likened making a contact to fishing, taking your time to get the rhythm of the other station, understanding that there's a human at the other end. Taking stock of what they're hearing, which stations they're responding to, how they respond and if they give out hints about making a successful contact with them.
<p>
The other day I came across a request to decode some Morse on an image showing long and short lines joined together in some form to serve an artistic purpose. Others pointed out that this wasn't Morse. I took an extra moment to point out that Morse had four individual attributes. It has a dit, a dah, a spacing between the letters and a spacing between the words, and since this image didn't have that it couldn't be Morse code. A few days later it occurred to me that I hadn't been paying attention. Morse actually has five attributes, it also has a spacing between each tone. I updated my answer and began to think about this interaction.
<p>
It's not the first time that I've stopped to consider what's happening.
<p>
For example, if I change bands on FT8, a digital mode that is very helpful for determining current propagation, I have a look at the level of activity. I'm generally not in a hurry, so I tend to leave it on the same band for a while, sometimes an hour, sometimes less, sometimes more. If the band is in full flight with every slot filled, it's easy to tick the "CQ Only" box and hide all the noise, or rather extra messages that form the exchange, but sometimes that noise has a whole lot of interesting information.
<p>
You can determine if one of the stations calling CQ is actually answering anyone or if they're just an alligator, all mouth, no ears. You can see individual people attempting to get each other's attention, making a local or a long distance contact. You can type in an interesting grid locator that accompanies most CQ calls and see just how far it is from you and in which direction.
<p>
I will also point out that using FT8 to observe a so-called dead band can be just as illustrative. It allows you to see signals in the waterfall, it decodes things that are barely visible and it will give you a feel for how your station at that location on that band at that time is performing in real-time. For example, it showed me that the squelch on my radio was turned on and blocking any chance of receiving weak signals, something that I wouldn't have noticed if I hadn't taken the time to observe.
<p>
Another example. During a contest I often take some time to listen to a pile-up that surrounds a massive station to see what stations I can hear, who is coming in strong and who is coming in weak. I keep a mental or actual note of what cracks the S-meter with an indication of signal strength and what only turns up as audio, perfectly readable, but not exciting the needle in any way. I might not speak with any of those stations, but I know that there are stations in a particular location that I can hear.
<p>
It's easy to get swept up in all this massive excitement that is our hobby, but sometimes it pays off to take a breath, to wait a moment, to take a look and have a listen to learn the lay of the land and understand what is happening and consider the implications. Within that moment of calm you might find an unexpected jewel in the rough. That's for example how I managed a contact with South Sudan several years ago during a massive pile-up in a club station during a contest.
<p>
I'd love to hear what you have stumbled upon serendipitously like that. You can always get in touch, cq@vk6flab.com is my address.
<p>
I'm Onno VK6FLAB
Listen:
Word of the day: software
Foundations of Amateur Radio
<p>
Every community has its own language. As a member of that community you learn the words, their meaning and their appropriate use. For example, the combination of words "Single Side Band" have a specific meaning inside amateur radio. Outside of radio, those same words are random words with no relationship.
<p>
Sometimes a term like "FM" can be heard across many communities with similar understanding, though not identical.
<p>
It gets tricky when a word is used widely but doesn't have a common understanding at all. A word like "software" for example.
<p>
A question you might hear in amateur radio is: "Can I buy a software defined radio or SDR that has digital modes built-in?"
<p>
It's a perfectly reasonable question, the radio runs software, the digital modes are software, so the answer is obvious, right?
<p>
What about: "Can the hundred or more computers in my car play Solitaire?"
<p>
Aside from the perhaps unexpected fact that your car has computers on board, you most likely know the answer to that. No, since the computers are specialised for different tasks - and if you're driving a Tesla right now, yes, you can play Solitaire, but I'd recommend that you keep your eyes on the road instead.
<p>
My point is that not all software is created equal.
<p>
The software inside an SDR is essentially doing signal processing, often by several components, each running software, transforming an antenna signal into something, that can be used somewhere else, likely sound.
<p>
The applications WSJT-X and fldigi, both software, use a computer running Linux, MacOS or Windows, software, to decode and encode digital modes while providing a way for you to interact with it. Software running on software.
<p>
You might well argue that we should be running applications like that directly on our radio and on the face of it that sounds perfectly reasonable, except that to achieve that, you'd also need to build a system to install and update different types of applications, so you could run SSTV, APRS, RTTY, PSK31, FT8 or any of the other hundreds of digital modes and new ones as they are developed.
<p>
If you did that, you'd also have to provide a way to manage the operating system, to connect to the Internet and provide security. You'd need to develop a user-interface, perhaps a keyboard and mouse solution, a screen, etc.
<p>
Before long you'll have developed a whole computing infrastructure, much like the one we already have in the form of the computer on your desk or the phone in your pocket.
<p>
Computers are getting faster and faster every day. This allows for the software on them to become more and more complex. The inter-dependencies are increasing by the second, but that doesn't mean that specialisation isn't useful.
<p>
A software defined radio likely has a Field Programmable Gate Array, an FPGA on-board that is great at processing data in streams. It too runs software. Your microwave is running software, as is your television, your smart-watch, your battery charger, the gearbox in your car and your electric tooth brush.
<p>
Making a distinction between the various types of software is helpful to understand what is possible and what is not. Being a computer nerd, I must point out that I've only barely scratched the surface of software here, in-case you're curious, microcode, firmware, hardware abstraction, the rabbit hole goes very deep.
<p>
Not all software is created equal and every now and then it's a good idea to remember that when you talk about a word in one community, it might mean a completely different thing in another and sometimes the distinction is significant.
<p>
As for having an SDR that runs WSPR, no. You can transmit from a computer though, but that's a whole other thing.
<p>
I'm Onno VK6FLAB
Listen:
How many hops in a jump?
Foundations of Amateur Radio
<p>
Amateur radio lives and dies with the ionosphere. It's drilled into you when you get your license, it's talked about endlessly, the sun impacts on it, life is bad when the solar cycle is low and great when it's not. There's sun spots, solar K and A indices, flux, different ionosperic bands and tools online that help you predict what's possible and how likely it is depending on the time of day, the frequency, your location and the curent state of the sun. If that's not enough, the geomagnetic field splits a radio wave in the ionosphere into two separate components, ordinary and extraordinary waves.
<p>
All that complexity aside, there's at least one thing we can all agree on. A radio wave can travel from your station, bounce off the ionosphere, come back to earth and do it again. This is known as a hop or a skip. If conditions are right, you can hop all the way around the globe.
<p>
I wanted to know how big a hop might be. If you know that it's a certain distance, then you can figure out if you can talk to a particular station or not, because the hop might be on the earth, or it might be in the ionosphere. Simple enough right?
<p>
My initial research unearthed the idea that a hop was 4000 km. So, if you were attempting to talk to a station at 2000 km or at 6000 km you couldn't do that with a hop of 4000 km.
<p>
If you've been on HF, we both know that's not the case.
<p>
If you need proof, which you really should be asking for, you should check out what the propagation looks like for any FT8 station, or any WSPR beacon over time and you'll notice that it's not 4000 km.
<p>
Just like the crazy network of interacting parameters associated with propagation, the distance of a hop can vary, not a little, but a lot.
<p>
In 1962, in the Journal of Geophysical Research D.B. Muldrew and R.G. Maliphant contributed an article titled: "Long-Distance One-Hop Ionospheric Radio-Wave Propagation". They found that in temperate regions such a hop might be 7500 km and in equatorial regions even 10,000 km.
<p>
I'm mentioning this because this was based on observations and measurements.
<p>
They used frequency sweeps from 2 to 49 MHz though they called them Mega Cycles, using 100 kHz per second, that is, over the duration of a second, the frequency changed by 100 kHz, so each sweep took nearly 8 minutes using only 15 kilowatts, so substantial gear, not to mention expense and availability.
<p>
Oh, computers, yes, they used those too. A three tonne behemoth called an IBM 650, mind you, that's only the base unit, consisting of a card reader, power supply and a console holding a magnetic drum unit.
<p>
You know I'm going somewhere with this right?
<p>
Today, you can do the same measurements with a $5 computer and a $20 receiver. For a transmitter, any HF capable radio will do the trick, though you might not be transmitting long if you stray outside the amateur bands. For power, 5 Watts is plenty to get the job done.
<p>
My point is that there is a debate around the future of our hobby and why modes like FT8 are such a controversial topic in some communities.
<p>
I'm here to point out that since that publication in 1962 our hobby has made some progress and we can improve on the work done by people who came before us. We could build a glob-spanning real-time propagation visualisation tool, we already have the data and modes like FT8 keep feeding in more.
<p>
If you're inclined, you could even make such a plot in real-time for your own station.
<p>
So, how long is a hop?
<p>
You'll just have to find out.
<p>
I'm Onno VK6FLAB
Listen:
You Can't Always Get What You Want
Foundations of Amateur Radio
<p>
One of the things about amateur radio that I find intensely fascinating and to be honest sometimes just as frustrating, is that you don't know what the outcome of an experiment might be at any one time. Not because you cannot control the experiment, or because you don't know what you're doing, but because the number of variables involved in most meaningful amateur radio experiments is pretty much infinite.
<p>
I've spoken about this before, the idea that if you were to make a simple dipole antenna and fold the ends on each other, you'd have infinite variation in antennas with just a so-called simple antenna, since you can vary the shape of it in an unending variety of ways.
<p>
The other day I was doing an experiment. An amateur radio one to be sure, but I was doing this within the realm of computing. I have been playing with digital modes for some time now and along the way shared some of what I've learnt. It occurred to me that I've been assuming that if you had the chance to follow along, you'd have access to the required hardware, simple enough, a $20 RTL-SDR dongle, but none-the-less, extra hardware.
<p>
What might happen if you rule out that dongle and instead used a web-based receiver like WebSDR, or KiwiSDR, or any number of other such sites where you can pretty much tune to any band and frequency and see what's going on at a particular antenna location.
<p>
For one it might allow you to decode something like APRS remotely, or decode an FT8 signal, perhaps even your own FT8 signal. Unfortunately most, if not all, of those sites include only the bare bones decoders for things like CW, AM, SSB and FM. After that you're pretty much on your own.
<p>
You could do some funky stuff with a web-browser, linking it via some mechanism to the tool you use to actually decode the sound and there's some examples of that around, none that I really warmed to, since it requires that I open a web browser, do the mouse-clicky thing and then set-up some audio processing stuff.
<p>
What if I wanted to figure out where the ISS was right now and wanted to listen to a receiver that was within the reception range of the ISS as it passed overhead, and automatically updated the receiver in real time as the ISS was orbiting the earth?
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For that to happen you'd need something like a command-line tool that could connect to something like a KiwiSDR, tune to the right frequency and extract the raw data that you could then decode with something appropriate.
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Turns out that I'm not the first person to think of this. There's even a project that outlines the idea of following a satellite, but it hasn't moved anywhere.
<p>
There's also a project that is a command-line client for web-based KiwiSDR sites, but after spending some quality time with it and its 25 clones on github, I'm not yet at the point where this will work. Mainly because the original author made a design decision to record data to a file with a specific name and any clone I've found thus far only allows you to define what name to use. None so far actually appear to send their stream to something that can be processed in real time.
<p>
Of course I could record a few minutes of data and process that, but then I'd have to deal with overlap, missing data, data that spans two files and a whole host of other issues, getting me further and further away of what I was trying to do, make a simple web-based audio stream digital mode decoder.
<p>
As the Rolling Stones put it, "You Can't Always Get What You Want"
<p>
And to me this sums up our hobby in a nutshell. When you call CQ, or go portable, or test an antenna, or attempt to build something new, there's going to be setbacks and unexpected hurdles.
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I think that it is important to remember that amateur radio isn't finished, it's not turn-key, no matter how much that appeals, you cannot find a one size fits all solution for anything, not now, not yesterday and not tomorrow.
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This hobby is always going to test boundaries, not only of physics, but your boundaries. It's after all one giant experiment.
<p>
So, next time you don't get what you want, you might try something you find, and get what you need.
<p>
Also, apologies to Keith Richards and Mick Jagger for butchering their words, a rockstar I am not.
<p>
I'm Onno VK6FLAB
Listen:
Running out of things to do ...
Foundations of Amateur Radio
<p>
So, there's nothing on TV, the bands are dead, nobody is answering your CQ, you're bored and it's all too hard. You've run out of things to try, there's only so many different ways to use the radio and it's all too much.
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I mean, you've only got CW, AM, SSB, FM, there's Upper and Lower Side-band, then there's RTTY, the all too popular FT8, then there's WSPR, but then you run out of things. I mean, right?
<p>
What about PSK31, SSTV, then there's AMTOR, Hellschreiber, Clover, Olivia, Thor, MFSK, Contestia, the long time favourites of Echolink and IRLP, not to forget Fusion, DMR, D-STAR, AllStar, BrandMeister or APRS.
<p>
So far I've mentioned about 20 modes, picked at random, some from the list of modes that the software Fldigi supports. Some of these don't even show up on the Signal Wiki which has a list of about 70 amateur modes.
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With all the bands you have available, there's plenty of different things to play with. All. The. Time.
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There's contests for many of them, so once you've got it working, you can see how well you go.
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Over the past year I've been experimenting with a friend with various modes, some more successful than others. I'm mentioning this because it's not difficult to get started. Seriously, it's not.
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The most important part of this whole experiment is getting your computer to talk to your radio. If you have FT8 already working you have all the hardware in place. To make the software work, you can't go past installing Fldigi. As a tool it works a lot like what you're familiar with. You'll see a band-scope, a list of frequencies and a list of decodes. It's one of many programs that can decode and generate a multitude of amateur digital modes.
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If this is all completely new to you, don't be alarmed.
<p>
There are essentially two types of connections between your computer and your radio. The first one is audio, the second is control. For this to work well, both these need to be two-way, so you can both decode the audio that the radio receives and generate audio that the radio can transmit. The same is true for the control connection. You need to be able to set the transmit frequency and the mode and you need to be able to read the current state of the radio, if only to toggle the transmitter on-and-off. If you already have CAT control working, that's one half done.
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I've spoken with plenty of amateurs who are reluctant to do any of this. If this is you, don't be afraid. It's like the first time you keyed up you radio. Remember the excitement? You can relive that experience, no matter how long you've been an amateur.
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Depending on the age of your radio, you might find that there is only one physical connection between your computer and the radio, either using USB or even Ethernet. You'll find that your computer will still need to deal with the two types of information separately.
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Notice that I've not talked about what kind of operating system you need to be running. I use and prefer Linux, but you can do this on any operating system, even using a mobile phone if that takes your fancy.
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Getting on air and making noise using your microphone is one option, but doing this using computer control will open you to scores of new adventures.
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I will add some words of caution here.
<p>
In general, especially using digital modes, less is more. If you drive the audio too high you'll splatter all over the place and nobody will hear you, well, actually, everyone will, but nobody will be able to talk to you because they won't be able to decode it. If the ALC on your radio is active, you're too loud. WSJT-X, the tool for modes like FT8 and WSPR, has a really easy way of ensuring that your levels are right, so if you've not done anything yet, start there.
<p>
Another issue is signal isolation. What I mean by that is you blowing up your computer because the RF travelled unexpectedly back up the serial or audio cable and caused all manner of grief. You can get all fancy with optical isolation and at some point you should, but until then, dial the power down to QRP levels, 5 Watts, and you'll be fine.
<p>
A third issue that was likely covered during your licensing is the duty cycle. It's the amount of time that your radio is transmitting continuously as compared to receiving only. For some modes, like WSPR for example, you'll be transmitting for a full 2 minutes at 100%, so you'll be working your radio hard. Even harder might unexpectedly be using FT8, which transmits in 15 second bursts every 15 seconds, so there may not be enough time for your radio to cool down. Investing in a fan is a good plan, but being aware of the issue will go a long way to keeping the magic smoke inside your radio.
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I'm sure that you have plenty of questions after all that.
<p>
You can ask your friends, or drop me an email, cq@vk6flab.com and I'll be happy to point you in the right direction.
<p>
Next time there's nothing good on TV, get on air and make some digital noise!
<p>
I'm Onno VK6FLAB
Listen:
What's in a prediction?
Foundations of Amateur Radio
<p>
Over the past little while I've been experimenting with various tools that decode radio signals. For some of those tools the signals come from space. Equipment in space is moving all the time, which means that the thing you want to hear isn't always in range.
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For example.
<p>
The International Space Station or ISS has a typical orbit of 90 minutes. Several times a day there's a pass. That means that it's somewhere within receiving range of my station. It might be very close to the horizon and only visible for a few seconds, or it might be directly overhead and visible for 10 minutes. If it's transmitting APRS on a particular frequency, it can be decoded using something like multimon-ng. If it's transmitting Slow Scan TV, qsstv can do the decoding. I've done this and I must say, it's exciting to see a picture come in line-by-line, highly recommended.
<p>
The National Oceanic and Atmospheric Administration or NOAA, has a fleet of satellites in a polar orbit that lasts about 102 minutes and they're overhead at least every 12 hours. You can use something like noaa-apt to decode the images coming from the various weather satellites, or a python script and I'll talk about that at some point.
<p>
There is a growing cloud of cube satellites with interesting telemetry. They're in all kinds of orbits and you can attempt to receive data from each one as it's in sight.
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Keeping track of what's where and when is a full time job for plenty of people. As a radio amateur I'm happy to defer to the experts who tell me where a piece of equipment is and when I'm likely to be able to receive a radio signal from the transmitter I'm interested in.
<p>
Previously I've mentioned in passing a tool called gpredict that does this heavy lifting for me. It presents a map of the world and shows what's visible at my location and when the next acquisition of signal for a particular satellite might occur. It talks to the internet to download the latest orbital information. It also has the ability to control a rotator to point your antenna, not that I have one, and it can update the transmit and receive frequency of your radio to compensate for the Doppler effect that changes the observed frequency as a satellite passes overhead. All this works with a graphical user-interface, that is to say, you have a screen that you're looking at and can click on.
<p>
Whilst running gpredict, you can simultaneously launch the appropriate decoding tool for the signal that you're trying to receive. If you have a powerful enough computer, you can run multiple decoding tools together. You'll have separate windows for controlling the radio and antenna, for decoding APRS, SSTV, NOAA and if you're wanting to do sunrise and sunset propagation testing using WSPR, you can also run WSJT-X or any other decoder you're interested in.
<p>
There are some implications associated with doing this, apart from needing a big enough screen, needing considerable computing power and burning electricity for no good reason, the signal that comes in from your radio will be fed to all the decoders at the same time and all of them will attempt to decode the signal, even when you know that this serves no purpose. That's fine if you don't know what you're listening to, but most of the time you know exactly what it is, even if the software doesn't.
<p>
Manually launching and quitting decoders is one option, but what if the next ISS pass is at 3am?
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Aside from the computing requirements, so far this works fine with a standard analogue radio like my Yaesu FT-857d. The only limitation is that you can only receive one station at a time.
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If you replace the analogue radio with an RTL-SDR dongle, you gain the ability to record and decode simultaneous stations within about 2.4 MHz of each other.
<p>
Another option is to use an ADALM Pluto and as long as the stations are within 20 MHz of each other, you can record and decode their signals. If you're not familiar with a Pluto, it's essentially a computer, receiver and transmitter, all in a little box, the size of a pack of cards.
<p>
This is where it gets interesting.
<p>
The Pluto doesn't have a screen, or a keyboard for that matter, but it's a computer. It runs Linux and you can run decoders on it. I've done this with ADS-B signals using a tool called dump1090. You'll find it on my GitHub page.
<p>
One of the sticking points in decoding signals from space was the ability to predict when a satellite pass occurs without requiring a computer screen. Thanks to a command-line tool called "predict", written by John, KD2BD and others I've now discovered a way to achieve that. My efforts are not quite at the point of show-and-tell, but I've got a Docker container that's building and running predict on its own and using a little bash script it's telling me when the ISS is overhead. You'll find that on GitHub as well.
<p>
My next challenge is to do some automated decoding of actual space signals. I'm going to start with the ISS, predict and multimon-ng. I'll let you know how I go.
<p>
What space signals are you interested in?
<p>
I'm Onno VK6FLAB
Listen:
Changing of the guard ...
Foundations of Amateur Radio
<p>
When you begin your journey as a radio amateur you're introduced to the concept of a mode.
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A mode is a catch-all phrase that describes a way of encoding information into radio signals.
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Even if you're not familiar with amateur radio, you've come across modes, although you might not have known at the time.
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When you tune to the AM band, you're picking a set of frequencies, but also a mode, the AM mode. When you tune to the FM band, you do a similar thing, set of frequencies, different mode, FM. The same is true when you turn on your satellite TV receiver, you're likely using a mode called DVB-S. For digital TV, the mode is likely DVB-T and for digital radio it's something like DAB or DAB+.
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Even when you use your mobile phone it too is using a mode, be it CDMA, GSM, LTE and plenty of others.
<p>
Each of these modes is shared within the community so that equipment can exchange information. Initially many of these modes were built around voice communication, but increasingly, even the basic mobile phone modes, are built around data. Today, even if you're talking on your phone, the actual information being exchanged using radio is of a digital nature.
<p>
Most of these modes are pretty static. That's not to say that they don't evolve, but the speed at which that happens is pretty sedate.
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In contrast, a mode like Wi-Fi has seen the explosion of different versions. During the first 20 years there were about 19 different versions of Wi-Fi. You'll recognise them as 802.11a, b, g, j, y, n, p, ad, ac and plenty more.
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I mention Wi-Fi to illustrate just how frustrating changing a mode is for the end-user. You buy a gadget, but it's not compatible with the particular Wi-Fi mode that the rest of your gear is using.
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It's pretty much the only end-user facing mode that changes so often as to make it hard to keep up. As bad as that might be, there is coordination happening with standards bodies involved making it possible to purchase the latest Wi-Fi equipment from a multitude of manufacturers.
<p>
In amateur radio there are amateur specific modes, like RTTY, PSK31, even CW is a mode. And just like with Wi-Fi, they evolve. There's RTTY-45, RTTY-50 and RTTY-75 Wide and Narrow, when you might have thought that there was only one RTTY. The FLDIGI software supports 18 different Olivia modes out of the box which haven't changed for a decade or so.
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The speed of the evolution of Olivia is slow. The speed of the evolution of RTTY is slower still, CW is not moving at all. At the other end new amateur modes are being developed daily.
<p>
The JT modes for example are by comparison evolving at breakneck speed, to the point where they aren't even available in the latest versions of the software, for example FSK441, introduced in 2001 vanished at some point, superseded by a different mode, MSK144. It's hard to say exactly when this happened, I searched through 15 different releases and couldn't come up with anything more definitive than the first mention of MSK144 in v1.7.0, apparently released in 2015.
<p>
My point is that in amateur radio terms there are modes that are not changing at all and modes that are changing so fast that research is being published after the mode has been depreciated. Mike, WB2FKO published his research "Meteor scatter communication with very short pings" comparing the two modes FSK441 and MSK144 in September 2020, it makes for interesting reading.
<p>
There are parallels between the introduction of computing and the process of archiving. The early 1980's saw a proliferation of hardware, software, books and processes that exploded into the community. With that came a phenomenon that lasted at least a decade, if not longer, where archives of these items don't exist because nobody thought to keep them. Floppy discs thrown out, books shredded, magazines discarded, knowledge lost.
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It didn't just happen in the 1980's. Much of the information that landed man on the moon is lost. We cannot today build a Saturn V rocket with all the support systems needed to land on the moon from scratch, even if we wanted to. We have lost manufacturing processes, the ability to decode magnetic tapes and lost the people who did the work through retirement and death, not to mention company collapses and mergers.
<p>
Today we're in the middle of a golden age of radio modes. Each new mode with more features and performance. In reality this means that your radio that came with CW, AM, FM and SSB will continue to work, but if it came with a specialised mode like FSK441, you're likely to run out of friends to communicate with when the mode is depreciated in favour of something new.
<p>
In my opinion, Open Source software and hardware is vitally important in this fast moving field and if we're not careful we will repeat history and lose the knowledge and skill won through perseverance and determination due to lack of documentation or depreciation by a supplier.
<p>
When did you last document what you did? What will happen to that when you too become a silent key?
<p>
I'm Onno VK6FLAB
Listen:
The Vagabond HAM
Foundations of Amateur Radio
<p>
This podcast began life under the name "What use is an F-call?" and was renamed to "Foundations of Amateur Radio" after 206 episodes. To mark what is effectively this, the 500th episode, I considered a retrospective, highlighting some of the things that have happened over the past decade of my life as a radio amateur. I considered marking it by giving individual credit to all those amateurs who have helped me along the way by contacting me, documenting things, asking questions, sharing their experiences or participating in events I attended. Whilst all these have merit, and I should take this opportunity to thank you personally for your contribution, great or small, to amateur radio, to my experience and that of the community. Thank you for making it possible for me to make 500 episodes, for welcoming me into the community, for being a fellow amateur. Thank you.
<p>
During the week I received an email from Sunil VU3ZAN who shared with me something evocative with the encouragement to bring it the attention and appreciation it deserves.
<p>
By way of introduction, on the 13th of June 2002, Ken, W6NKE became a silent key. Ken was an amateur, an active one by all accounts. I never met Ken, but his activity list is long and varied. Ken became interested in ham radio as a teenager in the 1930s. He was a long time advocate of CW and during WWII he taught Morse code to Navy operators. In 1975 he founded The Sherlock Holmes Wireless Society and was editor of its newsletter, now called "The Log of the Canonical Hams". He received his Investiture from The Baker Street Irregulars in 1981. Ken was an early member of the International Morse Preservation Society or FISTS, he held number 0818. He was the President of Chapter 2 of the Old Old Timers Club, the OOTC for many years. In addition to drawing cover art, Ken also wrote. Lots. 73 magazine features plenty of Ken's articles with titles like: "Inexpensive Vertical", "Don't Bug me Dad" and "The DX Hunter".
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Ken was also a poet, which brings us to the way that I think is appropriate to mark the 500th episode of this podcast. I'm confident that you can relate to this contribution by Ken to amateur radio, published in Volume 1, Number 3 of 73 magazine in December 1960.
<p>
<p>
The Vagabond HAM, by Ken Johnson W6NKE (SK)
<p>
A vagabond's life is the life I live
Along with others, ready to give
A friendly laugh and a word of cheer
To each vagabond friend, both far and near.
<p>
I travel the air waves, day or night
To visit places I'll never sight
From the rail of a ship, or from a plane
Yet I'll visit them all again and again.
<p>
I never hear from a far off land
That my pulse doesn't quicken. With careful hand
I tune my receiver and VFO dial
To make a new friend and chat for awhile.
<p>
Africa, Asia, they're all quite near
In as easy reach as my radio gear
With the flip of a switch, the turn of a knob
I can work a ZL, a friend named Bob.
<p>
There's an LU4, a fellow that's grand
Who's described to me his native land
'Till I can hear the birds, and feel the breeze
As it blows from the slopes of the mighty Andes.
<p>
I learned of the surf, and a coral strand,
The smell of hybiscus where palm trees stand
'Neath a tropical moon, silver and bright
From an FO8 that I worked one night.
<p>
I've thrilled to the tales of night birds' screams
In the depths of the jungle where death-laden streams
Flow'neath verdant growth of browns and greens
From a DU6 in the Philippines.
<p>
The moors of Scotland, a little French Shrine,
German castles on the River Rhine
Of these things I've learned, over the air
Without ever leaving my ham shack chair.
<p>
There's a KL7 on top of the world
To whom the Northern Lights are a banner unfurled
That sweeps across the Arctic night
Makes the frozen sky a thing of delight.
<p>
Tales of silver and gold and precious stones
Ancient temples and molding bones
Where the natives, I'm told, are tall and tan
By an XE3 down in Yucatan.
<p>
My vagabond trips over the air
Will take me, well, just anywhere
Where other vagabonds and I will meet
From a tropical isle, to a city street.
<p>
My vagabond's life will continue, I know
Through the fabulous hobby of ham radio
And one day from out at the world's end
We'll meet on the air, my Vagabond friend.
<p>
<p>
<p>
I'm Onno VK6FLAB
<p>
Note: The spelling of the poem is as published in 73 magazine.
Listen:
The APRS of it all ...
Foundations of Amateur Radio
<p>
Amateur radio is a living anachronism. We have this heady mix of ancient and bleeding edge, never more evident than in a digital mode called Automatic Packet Reporting System or APRS. It's an amateur mode that's used all over the place to exchange messages like GPS coordinates, radio balloon and vehicle tracking data, battery voltages, weather station telemetry, text, bulletins and increasingly other information as part of the expanding universe of the Internet Of Things.
<p>
There are mechanisms for message priority, point-to-point messages, announcements and when internet connected computers are involved, solutions for mapping, email and other integrations. The International Space Station has an APRS repeater on-board. You'll also find disaster management like fire fighting, earthquake and propagation reporting uses for APRS. There's tools like an SMS gateway that allows you to send SMS via APRS if you're out of mobile range. There's software around that allows you to post to Twitter from APRS. You can even generate APRS packets using your mobile phone.
<p>
In my radio travels I'd come across the aprs.fi website many times. It's a place that shows you various devices on the APRS network. You can see vehicles as they move around, radio repeater information, weather, even historic charts of messages, so you can see temperatures over time, or battery voltage, or solar power generation, or whatever the specific APRS device is sending.
<p>
As part of my exploration into all things new and exciting I thought I'd start a new adventure with attempting to listen to the APRS repeater on the International Space Station. I'm interested in decoding APRS packets. Seeing what's inside them and what kinds of messages I can hear in my shack. Specifically for the experiment at hand I wanted to hear what the ISS had to say.
<p>
After testing some recommended tools and after considerable time hunting I stumbled on multimon-ng. I should mention that it started life as multimon by Tom HB9JNX, which he wrote in 1996. In 2012 Elias Oenal wanted to use multimon to decode from his new RTL-SDR dongle and in the end he patched and brought the code into this century and multimon-ng was born. It's available on Linux, MacOS and Windows and it's under active development.
<p>
It's a single command-line tool that takes an audio input and produces a text output and it's a great way to see what's happening under the hood which is precisely what I want when I'm attempting to learn something new.
<p>
In this case, my computer was already configured with a radio. I can record what the radio receives from the computer microphone and I can play audio to the radio via the computer speaker. My magical tool, multimon-ng has the ability to record audio and decode it using a whole raft of in-built decoders. For my test I wanted to use the APRS decoder, cunningly disguised as an AFSK1200 de-modulator. I'll get to that in a moment.
<p>
The actual process is as simple as tuning your radio in FM mode to the local APRS frequency and telling multimon-ng to listen. Every minute or so you'll see an APRS packet or six turn up on your screen.
<p>
The process for the ISS is only slightly different in that the APRS frequency is affected by Doppler shift, so I used gpredict to change the frequency as required; multimon-ng continued to happily decode the audio signal.
<p>
I said that I'd get back to AFSK1200. The 1200 represents the speed, 1200 Baud. The AFSK represents Audio Frequency Shift Keying and it's a way to encode digital information by changing the frequency of an audio signal. One way to think of that is having two different tones, one representing a binary zero, the other representing a binary one. Play them over a loud-speaker and you have AFSK. Do that at 1200 Baud and you have AFSK1200.
<p>
When you do listen to AFSK and you know what a dial-up modem sounds like, it will come as no surprise that they use the same technique to encode digital information. Might have to dig up an old dial-up modem and hook it up to my radio one of these days.
<p>
Speaking of ancient. The hero of our story, APRS, dates back to the early days of microcomputers. The era of the first two computers in my life, the Apple II and the Commodore VIC-20. Bob WB4APR implemented the first ancestor of APRS on an Apple II in 1982. Then in 1984 he used a VIC-20 to report the position and status of horses in a 160km radius using APRS.
<p>
As for the International Space Station, the APRS repeater is currently switched off in favour of the cross-band voice repeater, so I'll have to wait a little longer to decode something from space.
<p>
I'm Onno VK6FLAB
Listen:
The other radios in the world ...
Foundations of Amateur Radio
<p>
When you join the community of radio amateurs you'll find a passionate group of people who to greater and lesser degree spend their time and energy playing with radios in whatever shape that takes. For some it involves building equipment, for others it means going on a hike and activating a park. Across all walks of life you'll find people who are licensed radio amateurs, each with their own take on what this hobby means.
<p>
Within that community it's easy to imagine that you're the centre of the world of radio. You know stuff, you do stuff, you invent stuff. As a community we're a place where people dream up weird and wonderful ideas and set about making them happen.
<p>
Radio amateurs have a long association with emergency services. When I joined the hobby over a decade ago one of the sales pitches made to me was that we're ready to be part of emergency communications. In some jurisdictions that's baked into the license.
<p>
There was a time when a radio amateur was expected to be ready to jump into a communications gap and render assistance with their station. There are amateur based groups groups like WICEN, the Wireless Institute Civil Emergency Network in Australia, ARES, the Amateur Radio Emergency Service in the United States, RAYNET, the Radio Amateurs' Emergency Network in the United Kingdom, AREDN, the Amateur Radio Emergency Data Network in Germany, DARES, the Dutch Amateur Radio Emergency Service, AREC or Amateur Radio Emergency Communications in New Zealand and EmComms in Trinidad and Tobago to name a few.
<p>
Each of those manages their participation in different ways. For example, ARES offers training and certification where AREDN offers software and a how-to guide, in Trinidad and Tobago the Office of Disaster Preparedness Management is actively involved in amateur radio and maintains an active amateur radio station and five repeaters.
<p>
In Australia there's a requirement to record and notify authorities if you become aware of a distress signal as a part of your license. In fact in Australia you must immediately cease all transmissions. You must continue to listen on frequency. You must record full details of the distress message, in writing and if possible recorded by tape recorder.
<p>
While that scenario can and has happened, it's not common. An amateur station being used to provide an emergency link in the case of catastrophic failure has also happened, but in Australia I'm not sure if that was in my lifetime or not.
<p>
My point is that the idea that we're going to put up a critical radio link and be the heart of communications in an emergency is, in Australia at least, not particularly likely. That's not to say that you should ignore that potential, or that it's universally true, but it's to point out that there are other things that you can do with your license that might happen more readily and help your community more.
<p>
Outside our amateur community, there's plenty of radio in use as well. The obvious ones are volunteer bush fire brigades, state emergency services and the like. Less obvious might be the local marine rescue group, surf life saving or the local council. Each of those use radios as part of their service delivery and a radio amateur can contribute to that without needing to bring their station along. In fact, if you don't have an amateur license, but want to play radio, that's an excellent place to do it as a volunteer. I should mention that radio procedures are also in use in all manner of other professions, mining, policing, the military and aviation to name a couple, not to forget occupations like tour-guides, ferry operators and pretty much any place where telephones, fixed or mobile are not readily deployed.
<p>
Within those areas there are procedures and jargon that you'll need to learn and perhaps even need to be certified for, but you as a radio amateur have several skills that you can bring to the table because you already have a license.
<p>
For example, I learnt my phonetic alphabet many years before I ever heard of amateur radio. It was a requirement for my aviation radio ticket which in turn was required before I flew solo. When it came to making my first ever transmission on amateur radio, doing the phonetic thing was second nature, much to the surprise of my fellow trainees at the time. A thank you is due to both Neil VK6BDO, now Silent Key, and Doug VK6DB for making that training happen.
<p>
You can apply the skills you bring with you when you join an organisation outside amateur radio who deals with wireless communication in whatever form that takes. For example, just the idea that you know how to pick up a microphone and push the Push To Talk button and speak and let the button go after you're done, a pretty trivial activity in amateur radio, will be something that you have that most of the untrained general public have no idea about.
<p>
Amateur radio is a massive hobby. Playing with radio, or doing something serious with it comes in all shapes and sizes. Your amateur experience can help, but be prepared to learn different procedures and methods. The amateur way isn't the only way and it's not the only place where radio is used and sometimes it's good to have a look outside your comfort zone and see what the neighbours are up to.
<p>
I'm Onno VK6FLAB
Listen:
The impossible task
Foundations of Amateur Radio
<p>
For decades I've been playing with every new piece of technology that comes my way. In amateur radio terms that's reflected in, among other things, playing with different antennas, radios, modes and software.
<p>
One of the modes I've played with is slow scan television or SSTV. It's an amateur mode that transmits pictures rather than voice over amateur radio.
<p>
A couple of months ago a local amateur, Adrian VK6XAM, set-up an SSTV repeater. The way it works is that you tune to the repeater frequency, listen for a while and when the frequency is clear, transmit an image. The repeater will receive your image and re-transmit it. It's an excellent way to test your gear and software, so I played with it and made it all work for me.
<p>
In 2012 I was part of a public event where local schools participated in a competition to have the opportunity to ask an astronaut on board the International Space Station a question as part of the City of Light 50th anniversary of John Glenn's first orbit. The event was under the auspices of a group called Amateur Radio on the International Space Station or ARISS, an organisation that celebrated its 20th anniversary in 2020.
<p>
Assisting with the logistics behind the scenes first hand and the amount of equipment used I'd gained a healthy respect for the complexity involved.
<p>
The ISS has several radio amateurs on orbit. Among their on board activities are plenty of amateur radio friendly ones. In addition to ARISS, you'll also find repeaters, voice, packet and other interesting signals if you listen out for them.
<p>
In previous years I've made abortive attempts at using my station to listen and transmit to space, with varying degrees of success.
<p>
On a regular basis the ISS transmits SSTV using amateur radio. Often you'll find a series of images that commemorate an activity. During the final week of 2020 astronauts on the ISS celebrated 20 years of ARISS by transmitting a series of images on a rotating basis as the ISS orbits the earth.
<p>
One of my friends made a throwaway comment about listening to the international space station and decoding slow scan television. I'd heard about this event on various social media outlets but put it in the too hard basket.
<p>
Based on what I'd seen during my ARISS event, my own trials, and what local amateurs have been playing with in the way of interesting cross polarised antennas, rotators and the like, I'd decided that this was a long term project, unachievable with my current station.
<p>
My station consists of a dual-band vertical antenna for 2m and 70cm on my roof at about 2m above ground level. The radio is my trusty Yaesu FT-857d. Connected to a Debian Linux laptop running three bits of software, rigctld, gpredict and qsstv.
<p>
With a high level of apprehension I fired up my station, tuned my radio, updated the orbital information and radio frequencies and waited for the first acquisition of signal from the ISS. Imagine my surprise when a picture started appearing on my screen. It's a lot like the days of 300 baud dial up, getting a picture from some remote computer back in 1985.
<p>
With that I managed to receive several of the images by just letting it run for the next couple of days.
<p>
I'm glad my friend made their comment, because it spurred me into action to try for myself.
<p>
I'll be the first to admit that the image quality isn't broadcast ready, or that I made mistakes, or that I should have started listening at the beginning of the week rather than the last few days, but all that is just noise because I can report that it works and I have the pictures to prove it!
<p>
I now have most of the image series, number 2 is missing and I only have part of number 1, but there are some beauties among the 35 images I captured. I've published them on my project website at vk6flab.com, for you to have a look at and use as inspiration for your own seemingly impossible task.
<p>
This leaves me wondering what else I can hear from overlying spacecraft using this set-up. What have you heard and what equipment were you using to make that happen? Are there any impossible tasks that you've avoided?
<p>
I'm Onno VK6FLAB
Listen:
Testing a link, on a band, at a time.
Foundations of Amateur Radio
<p>
The other day I wanted to know what kind of communication was possible between my station and the station of a friend of mine. We want to do some experiments and for that to be possible, we need to have a reliable communication channel.
<p>
Traditionally you would get in touch with each other and attempt to find a suitable frequency on a band to make a QSO or contact. That generally involves picking a band, then tuning around the band, finding a frequency that's not in use, then listening, asking if the frequency is in use, then telling your friend via an alternative method where you are, only to have them tell you that they have noise at that particular frequency. You go back and forth a couple of times, finally settle in on a mutually convenient frequency and have a contact whilst keeping note of the signal strength shown on your receiver.
<p>
On a good day that will take a few minutes, on a bad day that might take much longer or not work at all.
<p>
If you want to do this across multiple bands, you have the fun of doing this whole thing multiple times.
<p>
In case you're wondering, I've done this plenty of times and I will confess that it's an interesting combination of joy and frustration in attempting to get the answer to a pretty simple and common question: "Can I talk to my friend?"
<p>
In my shack there are plenty of tools, digital multimeters, LC meter, antenna analyser and the like. No doubt you have some or more of those. Perhaps you have an oscilloscope, a vector network analyser, or other gadgets.
<p>
None of those are particularly useful tools to solve this particular problem.
<p>
On the other hand, you are likely to have a receiver and probably a transmitter. If you're reading or listening to this, you're likely to have a computer as well.
<p>
Using a receiver and a computer as a tool to solve this problem might not have occurred to you. It hadn't occurred to me until recently that these are ideally suited for this particular repetitive task.
<p>
So, I fired up my copy of WSJT-X and set it to WSPR mode. Changed the band to 2m and set it up to transmit. The other station did the same. Within a couple of minutes the results were coming in. We could both see what the link quality was like between us. Then we changed to 70 cm and did it again. Rinse and repeat for 10m.
<p>
As it happens, the other station was receive only and they had to attend to some family activities and I was in my office earning a living, well actually, doing my bookkeeping, but you get the idea, you can do this test while you're doing something else.
<p>
I checked in a couple of times to see how it was going when he pointed out that I could see his actual results on the WSPRnet.org website.
<p>
I had been looking at the map with mixed results because it had been timing out for most of the day and when it did work, all I could see was that a message was decoded, not how well it was received. Randall VK6WR, the other station, then pointed me at the link to the database which I hadn't seen until then. If you're looking, it's at the top right.
<p>
Out pops a list of all the WSPR spots his station reported, and as a bonus, the spots reported by another local amateur.
<p>
If you know me at all it will come as no surprise that I used the opportunity to make a chart. Actually I made several, one showing the frequency drift between our stations, one showing the signal strength.
<p>
Between the three bands it looks like 2m gives us the best opportunity for experimentation, though 70cm does appear to have some possibilities. Sadly 10m isn't with the antennas currently in the air, but I saw an email the other day with reports of a new vertical at the other end, so we'll have a go at doing the 10m test again in the very near future, perhaps even today.
<p>
Right now from the WSPRnet.org website I'm downloading this month's WSPR reports from the Downloads section to see who else saw my signals. No doubt I'll make a chart or six. I'll keep you posted.
<p>
I must thank Randall VK6WR for pointing me at the database link on the WSPRnet.org website, because that made propagation and link testing so much more useful and repeatable.
<p>
Tools come in all shapes and sizes. What's one that unexpectedly helped you lately?
<p>
I'm Onno VK6FLAB
Listen:
When will it ever end?
Foundations of Amateur Radio
<p>
Mark Twain is often misquoted in relation to reports about his death, pithy as always, he said: "The report of my death was an exaggeration." Similarly the death of amateur radio has been reported on many different occasions.
<p>
Letting amateurs near a Morse key, banning spark-gap transmitters, introducing transistors, integrated circuits, computers, the internet, software defined radio, the list grows as technology evolves. I can imagine our descendants decrying the death of amateur radio with the commodification of quantum computing at some point in the future of humanity.
<p>
Yesterday I had an entertaining and instructional play date with a fellow amateur. We discussed countless aspects of our hobby, things like how you'd go about direction finding if you had access to multiple radios and antennas, what characteristics that might have, what you'd need in the way of mathematics, how you'd write software to solve the problem and how you'd go about calibrating such a system. Could you use a local AM broadcast station as a calibration source, or do you need to generate a known signal?
<p>
We started talking about how you'd send data across the network so you could have a dozen devices in different locations that you could synchronise and share data. How would you control it, how would you make use of existing standards, were there other tools like this already and what were their limitations.
<p>
Then there was the conversation about using spectrum effectively, seeing current digital modes like FT8 and their level of effective use of a 2.5kHz slice of spectrum with 15 second time-slots and the theoretical bandwidth that you might achieve if you used that mode as a data transmission mode.
<p>
There was the conversation around how you'd use propagation tools to determine path openings on the higher bands without needing a beacon, just a computer and a radio.
<p>
Then we talked about how you'd go about making a simple WSPR beacon, based on a minimum component count and some readily available hardware, rather than a sophisticated transceiver like a PlutoSDR.
<p>
There was a discussion around E-class amplifiers and their characteristics and potential pitfalls.
<p>
We managed to cover a fair bit of ground in a few hours over our hot beverage of choice, a nice meal for lunch and despite me tripping over the threshold of my front door, banging my head against the wall and rolling my ankle. The head is fine, the ankle not so much.
<p>
My point is that the world of amateur radio is never done, it's never finished, there's never an end. There's always more to discover, more to explore, build and investigate.
<p>
How on earth could you contemplate that this was a hobby that had no relevance in the world today, let alone that of tomorrow.
<p>
I for one am very happy to call myself an amateur and looking forward to discovering what else there is to play with. Why are you an amateur and does this feel like the end or a new beginning every day?
<p>
The reports of the death of amateur radio was an exaggeration.
<p>
I'm Onno VK6FLAB
Listen:
If you want to do HF in an apartment, where do you start?
Foundations of Amateur Radio
<p>
One of the many vexing issues associated with getting on-air and making noise is actually making that happen.
<p>
So, let's look at a completely restricted environment. An apartment building, seven stories off the ground, no ability to make holes, an unsympathetic council, restrictive local home owners association, et cetera, et cetera.
<p>
On the face of it your amateur radio hobby is doomed from the start.
<p>
In reality, it's only just beginning.
<p>
So, to hear HF right now, today, you can go online and listen to a plethora of web-based software defined radios. There's the canonical WebSDR in Twente and a whole host of others using the same or similar software. There's KiwiSDR, AirSpy, Global Tuners, and many more.
<p>
This will give you countless radios to play with, coverage across the globe, the ability to compare signals from different receivers at the same time on the same frequency, the ability to decode digital modes, find propagation, learn about how contests are done, the sky's the limit. I'll add that you don't need an amateur license for many of these resources, so if you're considering becoming part of the community of radio amateurs, this is a great way to dip your toe in the water. Think of it as a short-wave listening experience on steroids.
<p>
I hear you say, but that's not amateur radio.
<p>
To that I say, actually, it is. It's everything except a physical antenna at your shack or the ability to transmit.
<p>
Permit me a digression to the higher bands. If you want to listen to local repeaters on UHF and VHF, listen to DMR and Brandmeister, you'll find plenty of online resources as well. You can often use a hand-held radio to connect to a local repeater which can get you onto the global Echolink, IRLP and AllStar networks. Failing that, there's phone apps to make that connection instead.
<p>
Of course if you want to expand your repertoire to transmission, beyond a hand-held, you can.
<p>
There are online transmitters as well. Many clubs have their club station available for amateurs to use remotely using a tool like Remote Hams. You'll get access to a radio that's able to transmit and you'll be able to make contacts, even do digital modes and contests. You will require an amateur license and access to such a station. Some clubs will require that you pay towards the running of such a service and often you'll need to be a member.
<p>
Then there's actually going to the club, you know, physically, going to the club shack and twiddling physical knobs, though for plenty of clubs that's now also a computer since they're adopting software defined radios just like the rest of the community is. Using a radio via a computer can be achieved directly in the shack, but there's no reason to stay on-site. You can often use these radios from the comfort of your own shack.
<p>
If you do want to get physical with your own gear, receiving is pretty simple. A radio with a wire attached to it will get you listening to the local environment. I have for example a Raspberry Pi connected to an RTL-SDR dongle that's connected to a wire antenna in my shack. It's listening across the bands 24/7 and reporting on what it hears.
<p>
If you want to use an actual transceiver and you don't have the ability to set-up an antenna, kit out your car and go mobile. Failing that, make a go-kit with batteries, which as an aside will stand you in good stead during an emergency. Take your go-kit camping, or climbing, or hiking. Plenty of opportunities to get on-air and make noise.
<p>
I hear you asking, what about having an antenna farm?
<p>
Well, you can set one up in a farmers paddock and connect to it remotely - you will need permission from the land-owner - there's plenty of amateurs who use their country abode as a remote station.
<p>
If you want to make noise at your actual shack, the antenna might be a piece of wire hanging from the balcony after dark, or an antenna clamped to the railing. You can use a magnetic loop inside your house. Some enterprising amateurs have tuned up the gutters in their building, or made a flagpole vertical, or laid a coax antenna on the roof. Have a look for stealth antennas, there's a hundred years of amateurs facing the same problem.
<p>
My own station is very minimalist. There's literally a vertical antenna clamped to the steel patio. Using that I'm working the world with 5 Watts, 14,000 km on 10m, no kidding.
<p>
Getting on-air and making noise doesn't have to start and finish with a Yagi on a tower. There's plenty of other opportunities to be an active amateur.
<p>
I'm Onno VK6FLAB
Listen:
2m reciprocity and other assumptions
Foundations of Amateur Radio
<p>
Over the past nine and a half years I've been hosting a weekly radio net for new and returning amateurs. Called F-troop, it runs every Saturday morning at 0:00 UTC for an hour. Feel free to join in. The website is at http://ftroop.vk6flab.com.
<p>
In making the better part of six thousand contacts during that time I've learnt a few things about how nets work and how there are built-in assumptions about how a contact is made. There are several things that seem universally accepted that are not actually supported by the evidence and repeating them to new amateurs is unhelpful.
<p>
For example, there is an assumption that on 2m there is signal reciprocity. By that I mean, what you hear is what the other party hears. On HF, contrary to popular belief, this is also not universally true due to massive power and antenna differences and signal reports on FT8 bear that out - for example, my signal is often reported at least 9 dB weaker than the other station.
<p>
The reason that on 2m this isn't the case is because in general there is at least one other transmitter involved, the repeater. If you're joining in via a remote network, either via RF or via the Internet, there are even more times when this isn't true, but let's stay with the simple scenario of a single repeater and two stations.
<p>
If I'm using a base-station with a fixed antenna, my connection to the repeater is rock-solid. If you are using a hand-held and you're on the move, your connection to the repeater is anyone's guess. It could be great, it could be poor or even non-existent.
<p>
Not only that, the repeater is often using higher power, sometimes much higher. On average the repeaters near me are using 30 Watts, the highest uses four times that, the lowest uses 10 Watts. In contrast, a handheld uses at most 5 Watts, but more likely than not, half that.
<p>
Receiving a strong signal on a hand-held is simple, transmitting a weak signal to a repeater is not.
<p>
The point is, you might be hearing me as-if I'm sitting next to you, but I might be hearing you on the other end of a really scratchy and poor, intermittent and interrupted link.
<p>
If you add other repeaters and links with differing volume or gain settings to the mix, you get the idea that a 2m conversation may in many ways act like a HF contact.
<p>
That implies that there are plenty of times when you should use phonetics to spell your callsign and anything else of interest, despite the often repeated assertion that you don't use phonetics on 2m.
<p>
Another assumption is that 2m is less formal than HF. The people you talk to on 2m are likely to be local, perhaps people you've met at a HAMfest, face-to-face. You recognise their voice, you know their situation, their station and their habits.
<p>
On HF however, you have contact with people across the globe, most of whom you've never met, will never meet, have no idea about, let alone have a relationship with. That's not to say that you cannot have a friend on HF, I have plenty of people whom I speak with on HF, often during a contest, whom I've never met, but whom I speak with regularly on air. I can similarly recognise their voice, their callsign and know what to expect.
<p>
The point is that the more you look at the differences between 2m and HF, the more you realise that they are the same. Interestingly, as an aside, a contact on 10m or 15m can on plenty of occasions sound like a strong local FM contact.
<p>
My advice is to not think of 2m as a "special" band, but to think of it as an amateur band with a set of conditions. By law you are required to announce your callsign every ten minutes and at the beginning and the end of each contact. Note that this doesn't mean at the beginning and end of each over. In case that doesn't make sense to you, a contact is the whole conversation from start to end. Each time a station transmits during that contact is an over.
<p>
You should vary how you identify yourself, using phonetics or not, at the minimum required interval, or on every over, depending on the circumstances, not depending on the band.
<p>
Look forward to making contact with you on what ever band. You can get in touch via email, cq@vk6flab.com is my address and if you're into Morse, this podcast is also available as a Morse-code audio file.
<p>
I'm Onno VK6FLAB
Listen:
Prior Planning Prevents Poor Performance
Foundations of Amateur Radio
<p>
The other day I was adding an item to my to-do list. The purpose of this list is to keep track of the things in my life that I'm interested in investigating or need to do or get to finish a project. My to-do list is like those of most of my fellow travellers, unending, unrelenting and never completed. As I tick off a completed item, three more get added and the list grows.
<p>
Given some spare time and to be honest, who has that, I am just as likely to find an item on my to-do list that was put there yesterday as an item that was put there 10 years ago. Seriously, as I migrate from platform to platform, my to-do list comes with me and it still has items on it that haven't been done in a decade, let alone describe what project it was for.
<p>
Of course I could just delete items older than x, but deciding what x should be is a challenge that I'm not yet willing to attack.
<p>
Anyway, I was adding an item to the list when I remembered seeing something interesting on the shed wall of a fellow amateur. There were two pieces of printed paper with a list of to-do items on it. Looking pretty much like my to-do list, except for one salient detail.
<p>
Each to-do list was for a different project.
<p>
At the time I spotted it I smiled quietly to myself and thought, yep, keeping track is getting harder for everyone.
<p>
Bubbling away in the back of my mind this notion of a to-do list for a single project kept nagging at me. Yesterday it occurred to me why it was nagging.
<p>
If you have a to-do list for every project then once the project is done, the to-do list is done. Not only that, the items on a project to-do list don't really grow in the same way as an unconstrained to-do list does.
<p>
It also has a few other benefits.
<p>
The sense of satisfaction towards completing a project is amplified as each item is ticked off and ultimately the project is done.
<p>
I'm sure that project managers already know this, might even have a name and a process for it. No doubt there are aspects that I've not considered, like for example, the never ending range of projects or the trap of a miscellaneous catch-all project, but I'll cross those bridges when I run into them.
<p>
As of right now, this gives me an improvement on my stifling life to-do list and it brings great satisfaction when I can tick off a whole project.
<p>
No doubt you've gotten to this point wondering what this has to do with amateur radio?
<p>
If it hasn't occurred to you, consider what's involved into setting up a portable power supply for when you activate on a field-day, what you need do to get logging working, what needs to happen to get ready for a contest, what you need to do when you're selecting your next radio, how you're going to prepare for the park activation next week and so-on.
<p>
If you have insights into this, feel free to get in touch. cq@vk6flab.com is my address. Speaking of me, did you know that "Foundations of Amateur Radio" is a weekly podcast and that we're up to episode 285? If you haven't already and you're itching to get your hands on even more content, before episode 1 there was another podcast, "What use is an F-call?"
<p>
It has 206 episodes and other than the name and my youthful self, the content is more amateur radio. If I've done everything right there won't be much in the way of overlap in those 491 episodes, other than the same unrelenting quest for new and exciting things to do with Amateur Radio, but then you already knew that.
<p>
Now where's my podcast to-do list?
<p>
* Tell you about "What use is an F-call?", tick.
* Tell you that I'm nearly at 500 episodes, tick.
* Finish recording this episode, tick.
<p>
I'm Onno VK6FLAB
Listen:
When one WSPR receiver just isn't enough
Foundations of Amateur Radio
<p>
When one WSPR receiver just isn't enough
<p>
The other day during a radio play date, highly recommended activity, getting together with friends, playing radio, seeing what you can learn, we were set-up in a park to do some testing. The idea was an extension on something that I've spoken about previously, using WSPR, Weak Signal Propagation Reporter, to test the capabilities of your station.
<p>
If you're not familiar with WSPR, it's a tool that uses your radio to receive digital signals from WSPR beacons across the radio spectrum. Your station receives a signal, decodes it and then reports what it heard to a central database. The same software can also be used to turn your station into a beacon, but in our case all we wanted was to receive.
<p>
If you leave the software running for a while you can hear stations across many bands all over the globe. You'll be able to learn what signal levels you can hear, in which direction and determine if there are any directions or bands that you can receive better than any other.
<p>
We set up this tool in a park using a laptop, a wire antenna and a radio running off a battery. In and of itself this is not particularly remarkable, it's something that has been done on a regular basis all over the globe, and it's something that I've been doing on-and-off for a few years.
<p>
What made this adventure different is that we were set-up portable about a kilometre up the road from the shack, whilst leaving the main WSPR receiver running with a permanent antenna.
<p>
This gave us two parallel streams of data from two receivers under our control, using different antennas in slightly different conditions, within the same grid-square, for the purpose of directly comparing the data between the two.
<p>
Over a couple of hours of data gathering we decoded 186 digital signals, pretty much evenly split between the two receivers. More importantly, the stations we heard were the same stations at the same time which gave us the ability to compare the two decoded signals to each other.
<p>
One of the aspects of using WSPR is that it decodes the information sent by a beacon. That information contains the transmitter power, the grid locator and the callsign. After the signal is decoded, the software calculates what the signal to noise ratio was of the information and records that, additionally giving you a distance and direction for each beacon for that particular transmission.
<p>
I created a chart that showed what the difference was between the two, plotted against the direction in which we heard the decode. This means that you can compare which antenna can hear what in which direction in direct comparison against the other.
<p>
In telling this story another friend pointed out that the same technique could be used to compare a horizontal vs. a vertical antenna, even compare multiple bands at the same time.
<p>
It looks like I might have to go and get myself a few more RTL-SDR dongles to do some more testing. If you don't have a spare device, there's also the option of comparing other WSPR stations that share a local grid square, so you can see what other people near you can hear and if you like, use it as an opportunity to investigate what antenna system they're using.
<p>
WSPR is a very interesting tool and putting it to use for more than just listening to a band is something that I'd recommend you consider. I've already created a stand-alone raspberry pi project which you can download from GitHub if you're itching to get started.
<p>
Thank you to Randall VK6WR for continuing to play and to Colin VK6FITN for expanding on an already excellent idea. If you would like to get in touch, please do, cq@vk6flab.com is my address.
<p>
I'm Onno VK6FLAB
Listen:
For that one special event ...
Foundations of Amateur Radio
<p>
Radio amateurs like to do new things, celebrate, remember, bring attention to, and overall have fun, any excuse to get on air. One of the things that we as a community do is setup our radios in weird and wonderful places, on boats, near light-houses, on top of mountains, in parks, you name it.
<p>
Another thing we do is create special callsigns to mark an occasion, any occasion.
<p>
For example, to mark the first time the then Western Australian Chief Scientist, Professor Lyn Beazley was on air she used the callsign VI6PROF.
<p>
When Wally VK6YS (SK) went on the air to educate the public about Rotary's End Polio Now campaign, he used VI6POLIO. More recently the Australian Rotarians of Amateur Radio operated VK65PFA, Polio Free Africa. When it's active, you'll find VA3FIRE to remind you of Fire Prevention Week in Canada, the Chinese Radio Amateurs Club operates B0CRA through to B9CRA which you can contact during the first week of May each year as part of the Chinese 5.5 Ham Festival.
<p>
We create callsigns for other things too.
<p>
Datta VU2DSI commemorates November 30th, the birthday of Indian physicist Sir Jagadish Chandra Bose named by the IEEE as one of the fathers of radio science, by operating a special callsign AU2JCB in his honour for a couple of weeks around the end of November.
<p>
I mention this because it's not hard to achieve. It's called a "Special Event Callsign" and many if not all amateur licensing authorities have provision for such a callsign. Rules differ from country to country, some say that the callsign must be for something of special significance to the amateur community, others require that it's of national or international significance. In Canada for example, if you're celebrating an anniversary, it must be a minimum of a 25th increment.
<p>
Different countries have different formats.
<p>
The USA for example issues temporary one by one calls consisting of a letter followed by a digit followed by a letter.
<p>
The UK offers GB and a digit followed by two or three letters. There's also "Special" Special Event Stations, which can have a format like GB100RSGB.
<p>
In Canada there's a whole system based on what kind of event, what region it's significant to, who's operating it, and so on.
<p>
In the Netherlands you can have a normal prefix followed by at most eight characters and an overall maximum length of twelve characters and you can have it for at most a year and only one at a time.
<p>
In Germany you can use a standard callsign pattern with a four to seven character suffix, but only for a limited time.
<p>
In Australia there's the traditional VI and a digit followed by any number of characters, but remember if you make it massive, getting it in the log is not always easy and using a digital mode like FT8 might not work as expected.
<p>
What ever you want to commemorate, celebrate or bring attention to, remember that your callsign is only one part of the process. Consider who's going to actually operate the callsign, if you're going to issue QSL cards, if there are awards or a contest associated with the callsign, if there needs to be a website, if this is a regular thing, or a once-off.
<p>
Another thing you need to consider is how you're going to publicise this callsign. There's no point in going to the effort of obtaining a special event callsign with nobody knowing about it, that's the whole point.
<p>
No matter which way you jump, there's always a large range of special event callsigns on the air at any one time and making contact with one is often a massive thrill for the person operating the callsign, not to mention the person making the contact.
<p>
So, if you have a chance to have a go, I'd encourage you to get on air with a special event callsign and make some noise!
<p>
I'm Onno VK6FLAB
Listen:
It lives ... crystal radio with three components
Foundations of Amateur Radio
<p>
The idea of building a crystal radio occurred to me a little while ago. I committed to building one, supplies permitting, before the end of the year. I can report that I now have a crystal radio. It works, as-in, I can hear a local AM broadcast station, and it took a grand total of three components costing a whopping two and a half bucks.
<p>
Before I get into it, this isn't glorious AM stereo, or even glorious AM mono, this is scratchy, discernible, unfiltered, temperamental radio, but I built it myself, from scratch and it worked first time.
<p>
Before I start describing what I did and how, I'm letting you know in advance that I'm not going to tell you which specific components to buy, since your electronics store is not likely to have the same components which would make it hard for you to figure out what would be a solid alternative if you didn't understand the how and why of it all.
<p>
So, disclaimer out of the way, my aim was to build a crystal radio using off the shelf components without needing to steal a razor blade, shave a cat, sharpen a pencil or any number of other weird contraptions. Not that those aren't potentially interesting as life pursuits, though the cats I know might object strongly, I wanted this to be about learning how this thing actually works without distraction.
<p>
I set about finding a capacitor and an inductor combination that made a resonant circuit with a frequency range that falls within the AM broadcast band. If you recall, you can make a high-pass filter from either a capacitor or an inductor. Similarly, you can make a low-pass filter from either component. If you line up their characteristics just so, you'll end up with a band-pass filter that lets the AM broadcast band pass through.
<p>
Now notice that I said range.
<p>
That means that there needs to be something that you can adjust.
<p>
In our case you can either adjust the inductor, or the capacitor, technically you could do both. My electronics store doesn't have variable inductors, so I opted for a variable capacitor.
<p>
The challenge becomes, which variable capacitor do you select with which inductor?
<p>
I used a spreadsheet to show what the bottom and the top range for each capacitor would be if combined with each inductor. This gave me a table showing a couple of combinations that gave me a range of resonance inside the AM band.
<p>
The formula you're looking for is the resonant frequency for a parallel LC circuit. Take the inductance and multiply that by the capacitance, then take the square root, multiply it by pi and again by two, then take the inverse and you'll have the resonant frequency. You'll need to pay attention to microhenry vs millihenry, and picofarad vs nanofarad and you'll also need to confirm that you've got kHz, MHz or just Hz out the other end, otherwise you'll end up several orders of magnitude in the wrong spot.
<p>
If you do all that, you'll likely end up with a couple combinations of inductor and capacitor that will do what you want.
<p>
Then when you head to the electronics store, you'll find that the stock you're looking for is end-of-life and that the colour coding on them isn't right, but if you manage to navigate that swamp, you'll come out the other end with a few parts in your hands.
<p>
Final bit you'll need is a diode. It acts as a so-called envelope detector. I'm not getting into it here, I'll leave that for another time, but a Schottky or Germanium diode is likely going to give you the best results for this experiment.
<p>
Wiring this contraption is pretty trivial. Start with joining the inductor and capacitor to each other in parallel, they'll act as the LC circuit. You can change the resonance by tweaking the variable capacitor. Then attach a long antenna wire to one end and an earth wire to the other end. Finally, connect the diode and an amplified loudspeaker in series between the LC antenna end and the LC earth end and your radio is done.
<p>
For my experiment the loudspeaker has a built-in amplifier, it's an external PC speaker with a power supply. I also had to keep my hand on the antenna to create enough signal - since essentially I'm a large body of water - great for being a surrogate antenna.
<p>
The unexpected thrill of hearing a local announcer coming through into my shack from three components lying on my desk was worth the anticipation. Highly recommended.
<p>
What are you waiting for?
<p>
I'm Onno VK6FLAB
Listen:
The excitement is palpable ...
Foundations of Amateur Radio
<p>
I'm looking at components. Not looking for, looking at. I have them sitting on the bench in front of me. A collection of six variable capacitors and six inductors. There's also a germanium diode, a breadboard, some connecting wires and two connectors.
<p>
I don't quite need that many capacitors or inductors and truth be told a breadboard is overkill, but I found myself getting into the spirit of things and for the tiny investment it seems like the thing to get whilst you're dipping your toe into the art of electronic circuit prototyping.
<p>
I am noticing something odd whilst I'm looking at these components, a familiar feeling in some ways, butterflies in my stomach. It's the exact same feeling as when I sit at the radio, getting ready to speak into the microphone just as I am starting a weekly radio net, something that I've now done about 480 times, not to mention the times when I did around 1600 interviews or broadcast live to the world, butterflies.
<p>
I'm mentioning this because in many ways this is a momentous event, not for the world, not for humanity, not even for the hobby, but for me. It's the first time I'm building a circuit completely from scratch, no pre-made circuit board, no pre-selected components, no building instructions, just me, some resonance formulas and the hope that I've understood what they represent and that the components I selected will do what my calculations say they should.
<p>
To make this even less exciting, there's no external power, nothing that's going to go boom or let magic smoke escape, nothing that will break if I get it wrong, but still.
<p>
The other day I received an email from Phil, WF3W. We have been exchanging email for a couple of years now. He's a member of the Mt Airy VHF Radio Club in Pennsylvania in the United States.
<p>
His email outlined an interesting question. What do new amateurs get excited about in this era of the ubiquitous world wide web? As a hobby we're attracting new members every day. Many of those are coming to the community by way of social media, rather than using things that are more traditionally considered radio like HF DX, making long distance contact using HF radio, rather than exchanging pithy emails or instant messages via the interconnectedness of the globe encompassing behemoth of the Internet.
<p>
The answer came easily to me, since last week we had a new amateur, Dave VK6DM who made his very first long distance HF contact between Australia and the United States. His level of excitement was contagious and that's something that I've found happens regularly.
<p>
Someone talks about magnetic loop antennas and the next thing six amateurs are building them. One person starts playing with satellites and before you know it YAGIs are being built and people are describing their adventures.
<p>
The same is true with my crystal radio. I've talked about it a couple of times and people are digging out their old kits and telling stories about how they grew up with their dad making a crystal radio.
<p>
That's what is exciting the new amateurs. The internet is just an excuse to find each other, just like F-troop is an excuse for people to turn on their communications tool of choice at midnight UTC on a Saturday morning to talk about amateur radio for an hour.
<p>
My excitement comes from trying new things and just like keying a microphone for the first time, there's this almost visceral experience of anticipation associated with starting.
<p>
I'm still working out how I want to build my new toy and how to go about testing to see if it actually works and what to look for if it doesn't. I'm trying hard to resist tooling up with crazy tools like signal generators and oscilloscopes, instead opting to use things I already have, like LC meters and my ears.
<p>
I can't wait until I can share how it goes.
<p>
I'm Onno VK6FLAB
Listen:
Antenna testing in the field.
Foundations of Amateur Radio
<p>
Antenna testing in the field.
<p>
If you've been around amateur radio for any time at all, you'll know that we spend an awful lot of time talking about antennas. How they work, where to get them, how to build them, how strong they are, how cheap they are, how effective, how resonant, you name it, we have a discussion about it.
<p>
It might not be immediately obvious why this is the case. An antenna is an antenna, right?
<p>
Well ... no.
<p>
Just like the infinite variety of cars on the road, the unending choice of mobile phones, ways to cook an egg and clothes to wear to avoid getting wet, antennas are designed and built for a specific purpose. I've talked at length about these variations, but in summary we can alter the dimensions to alter characteristics like frequency responsiveness, gain, weight, cost and a myriad of other parameters.
<p>
If we take a step back and look at two antennas, let's say a vertical and a horizontal dipole, we immediately see that the antennas are physically different, even if they're intended for exactly the same frequency range. Leaving cost and construction aside, how do you compare these two antennas in a meaningful way?
<p>
In the past I've suggested that you use a coax switch, a device that allows you to switch between two connectors and feed one or the other into your radio.
<p>
If you do this, you can select first one antenna, then the other and listen to their differences. If the difference is large enough, you'll be able to hear and some of the time it's absolutely obvious how they differ. You might find that a station on the other side of the planet is much stronger on one antenna than on the other, or that the noise level on one is much higher than the other. Based on the one measurement you might come to the conclusion that one antenna is "better" than the other.
<p>
If you did come to this conclusion, I can almost guarantee that you're wrong.
<p>
Why can I say this?
<p>
Because one of the aspects of the better antenna is dependent on something that you cannot control, the ionosphere, and it is changing all the time.
<p>
I have previously suggested that you listen to your antenna over the length of a day and notice how things change, but that is both time consuming and not very repeatable, nor does it give you anything but a fuzzy warm feeling, rather than an at least passing scientific comparison.
<p>
A much more effective way is to set up your station, configure it to monitor WSPR, or Weak Signal Propagation Reporter transmissions using one antenna, for say a week, then doing it again with the other antenna.
<p>
If you do this for long enough you can gather actual meaningful data to determine how your antenna performs during different conditions. You can use that knowledge to make more reliable choices when you're attempting to make contact with a rare station, or when it's 2 o'clock in the morning and you're trying to get another multiplier for the current contest.
<p>
You don't even have to do anything different and spend little or no money on the testing and data gathering.
<p>
You can do this with your normal radio and your computer running WSJT-X, or with a single board computer like a raspberry pi and an external DVB-T tuner, a so-called RTL-SDR dongle, or with an all-in-one ready-made piece of hardware that integrates all of this into a single circuit board.
<p>
If you want to get really fancy, you can even use automatic antenna switching to change antennas multiple times an hour and see in real-time what is going on.
<p>
You also don't have to wait until you have two antennas to compare. You can do this on a field day when you get together with friends who bring their own contraptions to the party.
<p>
If there's any doubt in your mind, you can start with a piece of wire sticking out the back of a dongle. I know, I'm looking at one right now. I've been receiving stations across the planet.
<p>
One thing I can guarantee is that the more you do this, the better you'll get a feel for how the bands change over time and how to go about selecting the right antenna for the job at the time.
<p>
I'm Onno VK6FLAB
Listen:
The making of a Crystal Radio
Foundations of Amateur Radio
<p>
Recently I made a commitment to building a crystal radio. That started a fevered discussion with several people who provided many helpful suggestions. This is the first time I'm building a crystal radio and to make things interesting I'm selecting my own components, and circuit diagram. What could possibly go wrong?
<p>
Crystal radios have been around for a while. Around 1894 Indian physicist Jagadish Chandra Bose was the first to use a crystal as a radio wave detector, using galena detectors to receive microwaves. He patented this in 1901. The advice I was given sometimes feels like it harks back to 1894, with suggestions of using cats whiskers, razor blades, and any number of other techniques that create the various components to make a so-called simple crystal radio.
<p>
At the other end of the scale there were suggestions to go to the local electronics store and buy a kit.
<p>
The first suggestions, rebuilding historic radios from parts made of unobtanium would mean many hours of yak shaving, just to get to the point of getting the components, rather than actually building the radio.
<p>
I realise that part of the experience is the journey and I'm sure that if my current project gets me hooked I'll look into it, but I really don't want to become that amateur who has a collection of home-brew crystal radios across the ages. Besides, I'm having a look at using my crystal radio as a front end to my software, so I want to keep sight of the radio part of what I'm doing, rather than the building part.
<p>
Before you get all hot and bothered, remember, amateur radio is a hobby that means different things to different people and for me I'm currently playing with software and I'm attempting to learn about the electronics principles that form the basis of our hobby.
<p>
As I said, the other end of the scale was to get a kit and build that. It has its appeal, but there's little in the way of learning and the construction part of things is pretty much putting together a kit which is something I first did when I constructed an LC meter kit a while ago. So that too doesn't really appeal to me.
<p>
Now comes the bit where I tell you what I've done to date.
<p>
On the physical side of things, nothing. On the thinking and learning and planning side, lots.
<p>
Here's where I'm at.
<p>
My current understanding of a crystal radio is that you need to detect the AM wave form of an RF frequency and pipe that into something that makes noise. Traditionally this is done with a crystal earpiece, but I saw someone use powered computer speakers with a built in amplifier, so I'm going to start with that as my first noise maker.
<p>
I should also mention that the crystal earpiece was a source of confusion. I thought that the crystal in crystal radio was referring to that one. It's not.
<p>
So, back to where I'm at. What do I need?
<p>
To start off, I cannot just connect an antenna to a speaker, since it will attempt to make sound for every known frequency, well, at least the ones that the antenna can handle that fit within the response envelope of the speaker and its amplifier. If you want to know what that sounds like, put your finger on the input plug to some powered speakers. Don't turn up the volume too loud, you'll regret it.
<p>
So step one is to make a way to only let specific frequencies through. I've previously discussed this. You might know it as a band-pass filter. You can make one using a capacitor and an inductor. If you make the capacitor variable, you can change what frequency passes. This is helpful because you don't want to be decoding more than one radio station at a time.
<p>
There are plenty of designs for crystal radios that offer hand wound inductors and home brew capacitors, but I'm not doing this to learn how to build those, I'm doing this because I want to learn how it works. I want to use readily available components from my local electronics store, so I started with building a spreadsheet that shows what the resonant frequency is for a combination of inductors and variable capacitors.
<p>
Today I learnt that I also need to pay attention to how wide this is, so I'll be revisiting this.
<p>
There are only two more components in my radio, a diode and another capacitor. The diode cuts off half of the information, since if you recall, AM uses two side-bands that are identical. At that point you have a signal that contains both the carrier and the audio signal. You need one last step, filter out the high frequency carrier. I've talked about that too, this is a low-pass filter. You can do this with a capacitor.
<p>
So, now we have the bare-bones of a crystal radio, made from four components, an inductor, a variable capacitor, a diode and another capacitor. My next challenge is to figure out what values they have so it will allow me to listen to my local AM radio station and do it using components off the shelf from my electronics store.
<p>
One thing I can tell you is that this is precisely why I signed up for this project. I don't want a ready-made radio from a kit and I don't want to have to learn how to chop down a tree in order to make a pencil.
<p>
I'll keep you posted. If you have additional reading material you'd like to suggest, feel free to get in touch.
<p>
I'm Onno VK6FLAB
Listen:
An ionospheric monitoring service at home
Foundations of Amateur Radio
<p>
One of the more fundamental aspects of long distance radio communication is the impact of the ionosphere. Depending on how excited the Sun is, what time of day it is and what frequency you're using at the time will determine if the signal you're trying to hear from the other side of the planet makes it to you or is on its way to a radio amateur on Proxima B who is likely to hear this podcast in just over 4 years from now.
<p>
In other words, the ionosphere can act like a mirror to radio waves, or it can be all but invisible.
<p>
As luck would have it, this changes all the time. Much like waiting for the local weather bureau for the forecast for tomorrow's field-day, there are several services that provide ionospheric predictions. The Australian Space Weather Service, SWS, is one of those. You might have previously known it as the Ionospheric Prediction Service, but Space is much more buzz-word compliant, so SWS is the go.
<p>
If you're not a radio amateur, space weather can impact stuff here on Earth, like the ability to communicate, transfer energy across the electricity grid, use navigation systems and other life-essentials. The SWS offers alerts for aviation and several other non-amateur services.
<p>
If you're interested in HF communications, the SWS offers HF prediction tools that allow you to check what frequencies to use to communicate with particular locations using visualisations like the Hourly Area Prediction map.
<p>
If you're more of the Do-It-Yourself kind of person, you might be pleasantly surprised that you can have your very own ionospheric monitoring station at home. Not only that, it's probably already in place, configured and ready to go.
<p>
If you're using WSJT-X to monitor WSPR transmissions, then you'll have noticed that the screen shows all the stations you've been able to decode and you can scroll back as far as you like to the time when you launched WSJT-X.
<p>
If you want to do some analysis on that, copy and paste is an option, but it turns out that there's a handy little document being stored on your computer called ALL_WSPR.TXT that contains the very same data going back to when you installed and launched the first time.
<p>
This information represents what stations you heard, at what time and with what level of signal to noise at your shack, not some fancy station in the middle of nowhere with specialist hardware, your actual station, the one you use to talk to your friends, with your antenna, your power supply, the whole thing.
<p>
For my own entertainment I've been working on a way to visualise this. I created a map that shows the location every station I've logged, 30,000 of these reports in the past four months. It's interesting to see that I can hear most of the globe from my shack. Notably absent is South America but that is likely a combination of band selection and local noise.
<p>
In the meantime I've gone down another rabbit hole in figuring out if I can use an image file to visualise all this without needing fancy software, unless you consider a web-browser and bash fancy.
<p>
The idea being that a simple script could take the output from your station and convert that into a map you can see on your browser. In case you're wondering, I'm thinking that a style-sheet attached to a Scalable Vector Graphic or SVG might be just the ticket to showing just how many times I've heard a particular grid-square.
<p>
If you have ideas on what else you might do with this data, get in touch.
<p>
I'm Onno VK6FLAB
Listen:
csdr will rock your world ...
Foundations of Amateur Radio
<p>
When you start playing with software defined radio, you're likely to begin your journey using something with a display that shows you a lovely waterfall, gives you a way to pick out a frequency, decode it and play it over your speakers all over the house. Likely your first effort involves a local FM radio station. These graphical tools come in many and varied forms available on pretty much anything with a display. Tools like SDR#, cuSDR, fldigi and WSJT-X.
<p>
That can be immensely satisfying as an experience.
<p>
Underneath the graphics is software that is essentially translating an antenna voltage to a sound, in much the same way as that happens in an analogue radio. There are the parts that get the signal, then they get translated and filtered, translated some more, decoded, and eventually you have sound coming from your speakers.
<p>
During the week I caught up with a fellow amateur who pointed me at the work of Andras HA7ILM who for a number of years has been quietly beavering away making various tools in the SDR landscape.
<p>
One of those tools has the innocuous name of "csdr", a command-line software defined radio digital signal processor. It started life on November 1st, 2014 and has had many updates and community changes since.
<p>
This tool has no graphics, no user interface, nothing visible that you can toggle with a mouse and yet it's one of the coolest tools I've seen in a long time and from a learning perspective, it's everything you might hope for and then some.
<p>
Before I explain how it works, I need to tell you about pipes. They're much like water pipes in your home, but in computing they're a tool that allow you to connect two programs together so you can exchange data between them.
<p>
One of the ways that you can think of a computer is a tool that transforms one type of information into another. This transformation can be trivial, like say adding up numbers, or it can be complex, like filtering out unwanted information.
<p>
The idea is that you take a stream of data and use a pipe to send it to a program that transforms it in some way, then use another pipe into another program and so on, until the original stream of numbers has become what you need them to be, creating a transformation pipeline with a string of programs that sequentially each do a little thing to the data.
<p>
That stream of data could be numbers that represent the voltage of the signal at your antenna and the final output could be sound coming from your speaker.
<p>
If you were to take that example, you could use one tool that knows how to measure voltage, pipe that to a tool that knows how to convert that into FM and pipe that to a tool that knows how to play audio on your speaker.
<p>
Converting something to FM is, in and of itself, a series of steps. It involves taking the raw numbers, extracting the part of the samples that are the station you want to hear, decoding those and converting that into something that is ready to be played on your speakers.
<p>
This process is fundamentally different from using a so-called monolithic tool that does everything behind the scenes. The person writing the software has decided what to do, how to do it, in what order and in what way. If you want to do something that the author hadn't thought of, like say listening to a new type of broadcast, you'll be waiting until they update the software.
<p>
In another way, this is the difference between making a cake from raw ingredients and buying it up the road at the shops
<p>
One final part of the puzzle.
<p>
There's nothing preventing you from piping the output of your program to another copy of the same program.
<p>
So, if you had a tool that knows how to do the maths behind filters, AM and FM decoding, translating Lower Side Band into Upper Side Band and vice-versa, band filtering, etc., you'd be able to set up individual steps that translate a signal, one step at a time, from raw antenna data into a sound you can hear. You would have all the building blocks for the fancy tools that you are used to.
<p>
csdr is such a tool.
<p>
For example, it knows how to set the gain of a signal, how to up and down sample, how to shift frequencies, how to decode them, it knows about RTTY, PSK, AM, FM and do about a hundred other things.
<p>
So far I've mentioned decoding, but there's nothing stopping you from starting with plain text, piping that into csdr and converting that to a PSK31 audio signal and transmitting that audio on your radio.
<p>
To make it even better, because it's so modular, you can look at the math behind what's going on and begin to understand what's happening behind the scenes.
<p>
Of all the tools I've found in the past decade, I have to confess, this is the one that has stopped me in my tracks.
<p>
Thank you to Randall VK6WR for introducing me to this tool and to Andras HA7ILM for writing it.
<p>
I'm Onno VK6FLAB
Listen:
New day, new mode ... SSTV
Foundations of Amateur Radio
<p>
In 1958 The Kentucky Engineer published an award winning student article by Copthorne "Coppie" MacDonald. He described a Slow-Scan T.V. System for Image Transmission. If you get the opportunity, have a look for the link on his archived home-page which you can find from the Wikipedia SSTV page.
<p>
The purpose of this narrow band television idea was to be able to send images using cheaper equipment and less bandwidth than normal television. The idea caught on and it's still in use today.
<p>
In 1959 the idea of slow scan tv was used by the Luna 3 mission to transmit images from the far side of the moon. The NASA Apollo program also used SSTV to transmit images from Apollo 7, 8, 9 and from the Apollo 11 Lunar Module.
<p>
In 1968 SSTV became a legal mode for radio amateurs in the United States.
<p>
The International Space Station regularly uses SSTV to send images to radio amateurs across the globe.
<p>
The version of SSTV in use by radio amateurs today is different from the earlier grainy black and white images coming from the moon and if you're expecting a moving image, something that TV implies, you're going to be disappointed, since the popular SSTV modes send images one at a time, taking up to a minute or so to send. With a frame-rate of one frame per minute, watching anything other than grass grow is going to be a challenge.
<p>
That said, SSTV is a lovely and relatively simple way of sending images across the air.
<p>
In my quest for new adventures I like to play with things I know nothing about. I suspect that it's ingrained but it does keep me off the street. The other day I received an email from a local amateur, Adrian VK6XAM, who sent a message describing a new SSTV repeater he'd set-up for testing purposes. It's a local 2m repeater that waits for an activation tone, then it expects you to transmit an SSTV image and it will replay the image back to you. If you've familiar with a parrot repeater, this is a similar thing, just for SSTV rather than audio. The repeater is running on solar power and with the 100% duty cycle of SSTV, it's only available during daylight hours.
<p>
Technicalities aside, I couldn't resist.
<p>
So, I fired up QSSTV, a piece of Linux software that among other things knows how to receive and send SSTV images. After turning on my radio, tuning to the correct frequency, I received my first ever SSTV picture.
<p>
On a bright red background a yellow symbol appeared. At first I thought it was a hammer and sickle, but on closer inspection it was a micrometer and caliper, which absolutely tickled my fancy, having just taken delivery of some precision measuring tools - a Mitutoyo Test Indicator and a few other bits and pieces for another project I'm working on.
<p>
Had to learn how to drive QSSTV, make a template so you can overlay text on an image, learn what a signal report should look like, then when I figured all that out I triumphantly hit send and it made all the right noises, but nothing was happening.
<p>
More time looking at the inter-web taught me that if I want to use the rear connection on my FT-857d to send audio using FM, as opposed to SSB which is what most digital modes need, you need to set the radio to PSK mode and magically it starts to work.
<p>
My first ever SSTV image was sent an hour and a half after receiving my first image and the repeater dutifully sent it back. Then I got a picture from Keith VK6WK.
<p>
Of course the paint isn't even dry on any of this, so there's plenty more to learn, but the process is not too complex.
<p>
I will note a few things.
<p>
I had already set-up digital modes, that is, my radio was talking to my computer via CAT, that's Computer Assisted Tuning, essentially a serial connection that controls the radio and the audio was already being sent and received from the rear connector of my radio.
<p>
Getting SSTV running was really an extension on those activities, so if you're going to do this, take some time to make things work. I continue to recommend that you start with WSJT-X since it helps you get your levels and connections right.
<p>
Now I suppose I should start playing with SSTV over HF, but first I would like to figure out how to make the templates work better for me and how to actually seriously log an actual contact.
<p>
More adventures ahead!
<p>
Remember, have fun, play, get on air and make noise!
<p>
I'm Onno VK6FLAB
Listen:
Simplicity among the complexity ...
Foundations of Amateur Radio
<p>
My radio shack consists of two radios, identical, well, in as much as that they're the same model, a Yaesu FT-857d. Their memories are different, their microphones are different, but both of them are connected via a coaxial switch to the same VHF and UHF antenna. One of them is also connected to a HF antenna.
<p>
Let's call these two radios alpha and bravo.
<p>
Alpha is used to host F-troop and play on the local repeater. Bravo is used to do HF stuff. It's also connected to a computer via a serial cable, called a CAT cable, Computer Assisted Tuning, but really, a way to control the radio remotely.
<p>
The audio output on the rear of the radio is also connected to the computer.
<p>
These two connections are combined to provide me with access to digital modes like PSK31, WSPR and SSTV, though I haven't actually yet made that work. The computer itself is running Linux and depending on what I'm doing on the radio some or other software, often it's fldigi, a cross-platform tool that knows about many different digital modes.
<p>
The computer is also connected to the Internet via Wi-Fi, and is used to see what various reporting websites have to say about my station, things like propagation, the DX cluster, an electronic way of seeing what other stations can hear, then there's solar radiation information and other neat tools.
<p>
This shack is pretty typical in my circle of friends. I'm lucky enough to have a dedicated table with my shack on it, for others they're lucky to have a shelf in a cupboard, or at the other end of the spectrum, a whole room or building dedicated to the task.
<p>
The level of complexity associated with this set-up is not extreme, let's call it in the middle of the range of things you can add to the system to add complexity.
<p>
In case you're wondering, you might consider automatic antenna switching, band switches, band filters, amplifiers, more radios, audio switching, automatic voice keyers. If you look at the world of Software Defined Radio, the hardware might include many of those things and then add a computer that's actually doing all the signal processing, making life even more complex.
<p>
At the other end of the complexity scale there's a crystal radio.
<p>
As I've been growing into this field of amateur radio it's becoming increasingly clear that we as a community, by enlarge, are heading towards maximum complexity.
<p>
There's nothing wrong with that as such, but as a QRP, or low-power operator, I often set-up my radio in a temporary setting like a car or a camp site. Complexity in the field is not to be sneezed at and I've lost count of the number of times where complexity has caused me to go off-air.
<p>
It occurred to me that it would be helpful to investigate a little bit more just what's possible at the other end of the scale, at the simple end of complexity if you like.
<p>
So, I'm intending, before the year is out, supplies permitting, to build a crystal radio from scratch. I realise that I have absolutely no idea what I'm getting myself into, no doubt there will be more complexity that I'm anticipating, but I'm getting myself ready to build something to be able to look at it and say to myself, look, this is how simple you can get with radio.
<p>
I'm currently too chicken to commit to making the simplest - legal - transmitter, but if you have suggestions, I'll look into it.
<p>
Just so you know, simplicity is an option.
<p>
I'm Onno VK6FLAB
Listen:
Yak Shaving ...
Foundations of Amateur Radio
<p>
Yak Shaving ...
<p>
Not every adventure gives you an outcome. Today started with reading a thank-you email from a listener who shared their activities and wanted to express their gratitude for encouraging them to get on air and make noise.
<p>
That in turn prompted the question on the country of origin of that listener and did I know where all my listeners were? For the past few hours I've been attempting to answer that seemingly simple question.
<p>
Aside from using the opportunity to make an attempt at mapping the distribution of amateurs in Australia, which on the face of it is a trivial exercise, consisting of extracting the postcode from each registered amateur and then putting those on a map.
<p>
Only the postcodes are not actually single points. They're boundaries defined by Australia Post and they're copyrighted. Not only that, they change. To access them, you have to pay the Post Office. If you want to combine a postcode with a population density, so you can see where amateurs are represented and at what level, you go to the Australian Bureau of Statistics for a population density data-set. At that point you realise that the Bureau uses standardised regions. Mesh-blocks at the smallest end of the scale are essentially the size of 30 to 60 households. The Bureau uses these as the fundamental size for all its statistics.
<p>
When you attempt to map this onto postcodes you learn that there isn't a one-to-one mapping and even if there was, it would change every time Australia Post changed a postcode boundary.
<p>
I will note that this is all by way of a side-street in my investigation. I wondered how amateur radio is distributed across the country and I didn't want to end up with essentially a population density map, more people means more amateurs, I wanted to see where amateur radio had the potential to affect more people because there are more of them in a group.
<p>
Anyway, then I attempted to look at the podcast downloads and map those to countries. I use AWS CloudFront to make the podcast available, so it gets to the user, you, quicker. The logs show which data-centre a request is handled by. Then I needed to map a data-centre to an airport code, look that up in a database so I could extract the country, then count how many requests were made per country.
<p>
Then I started doing that across time, so you can see how that changes over time.
<p>
At this point I still don't actually have a map to show.
<p>
While all this was happening, my computer started running low on disk-space, not because I'd just downloaded some data from the Australian Bureau of Statistics, but because some rogue process was writing a log somewhere, so I spent an hour looking for what process that was, killing it and removing the superfluous log file.
<p>
If this sounds familiar, there's a name for it. Yak shaving. It's originally named after a Ren and Stimpy episode called "Yak Shaving Day". Essentially you do a whole lot of unrelated activities in the pursuit of the actual activity, essentially a string of dependencies that distract you from the end-goal. In my case, trying to answer which countries are represented within my audience.
<p>
Why am I not using an amateur radio example?
<p>
Two reasons.
<p>
This is amateur radio. For me. Doing charts, wrangling data, massaging stats, finding answers and presenting those are an integral part of the hobby, to me. Just like making this podcast, contributing to discussion, reading and learning. All part of the mix.
<p>
Second reason is that I wanted to illustrate this with something that wasn't immediately obviously linked to the hobby for most people. A more amateur example might be wanting to go and operate portable, attempting to locate you battery, when you find that it's not charged, so you go looking for the charger which you find has a broken connector, so you drive to the electronics store to get the connector when you run out of petrol, so you pull over, get out of the car and trip over the curb and end up in hospital emergency waiting for a doctor to see you. If you think that's far-fetched, I know an amateur who ended up in hospital from yak-shaving.
<p>
We've all had days like that.
<p>
The idea is that any day that you are on the right side of the earth, doing something you love is a good day.
<p>
Regardless of the end result, this is a hobby after all.
<p>
I'm Onno VK6FLAB
Listen:
What is so different about using software for signal processing?
Foundations of Amateur Radio
<p>
In my ongoing software explorations I've discussed that Software Defined Radio or SDR is a fundamentally different way of dealing with radio. It's been in use across non-amateur circles for decades. Your mobile phone has an SDR on board for example.
<p>
The original term of "digital receiver" was coined in 1970, "software radio" was coined in 1984 and in 1991 Joe Mitola reinvented the term "software radio" for a planned mobile phone base station.
<p>
So, this idea has been around for half a century and in amateur radio this idea is also catching on. You can buy a few pure SDR devices today, some hybrid ones, or you can begin to experiment in a more indirect manner using your traditional radio and a computer.
<p>
One of the things that sets this idea of a software defined radio apart from anything we've done so far is that the bulk of the signal processing is done in software. That sounds obvious, but it's really not.
<p>
One of the impacts of this idea is that you can improve your radio communications by either writing better software, or by using a faster computer. Unless you write software for a living, these things aren't immediately obvious, so let me explain.
<p>
Imagine that you've written software that detects beeps in a particular slice of audio spectrum that's being fed to your application. As you write better software to detect those beeps, you get a better digital mode, one with a better chance of being decoded, or using radio terms, it has a better signal to noise ratio.
<p>
If that's not a familiar term, signal to noise ratio is the a measure that describes the difference between a wanted signal and the background noise. Higher signal to noise means that you can better distinguish between the two.
<p>
If you stand in a room full of people talking and you use your hands to cup your ears towards the person you want to hear, you've increased the signal to noise ratio and your chance of understanding them has improved.
<p>
As you write this software, it gains complexity. As you deal with more maths, more samples, more tests, you end up running out of time to make your decoder return a relevant answer. There's no point in having a real-time signal being decoded late. If it were to take say 10 seconds to decode 1 second of audio, then the next second would be 20 seconds late and the one after that would be 30 seconds late.
<p>
That's where a faster computer comes in.
<p>
If you have the ability to do more maths, or do the same maths at a higher resolution, you will essentially improve the reception of your radio without ever needing to change your antenna or anything on the circuit board.
<p>
Think of it in another way.
<p>
Imagine that your tool has access to 2.3 kHz of audio. It's the equivalent of a Single Side Band audio stream. If you break that down into 23 chunks of 100 Hz each, you can deal with the average of 100 Hz of audio for each calculation. If you have a faster computer, you might be able to break that down into 230 chunks of 10 Hz each, or 2300 chunks of 1 Hz. So instead of doing calculations across 23 chunks of audio, you're doing it across 2300 chunks.
<p>
Why is this significant you might ask?
<p>
Well, in a traditional radio you get one bite at the cookie. You get to design and build your circuit and then package it and sell it. The end result is something like my FT-857d. It does what it does well, but it will never get any better.
<p>
However, if I plug that same radio into my computer, I can extract the audio and do stuff with it. If I get a faster computer, I can do more stuff. I don't have to change my radio, or my antenna, or even my shack. Most of the time I run a different application and I get a different result.
<p>
I will point out that I'm deliberately ignoring where and how the RF gets to the computer, or where that computer actually is, or what operating system it's running, since none of those things matter to get an understanding of how changing software can change the performance of your radio.
<p>
I've said this before and I'll say it again: "The SDR earthquake will change our hobby forever"
<p>
Before I go. I'm not for a minute suggesting that your current radio is obsolete. If it were legal, a spark-gap transmitter could still exchange information today, but if you want to explore what might be just over the horizon, going down the SDR path by connecting your radio to your computer is a really nice place to start.
<p>
I'm Onno VK6FLAB
Listen:
When you run into a pounce ...
Foundations of Amateur Radio
<p>
Contesting is a fun way to learn about amateur radio. It tests your skill, your station, your patience and your ability to change approach at a moments notice. For those reasons alone it's an activity that I recommend you have a go at.
<p>
For me it's also about self-improvement. With each contest, can you make better use of your station, can you learn more about your radio, about bands, about conditions and ultimately become a better operator. I know that there are individuals who keep telling me that giving out signal reports of 5 and 9 isn't helpful, to them I say, try it in a contest setting and see what else you learn.
<p>
When you start out contesting you'll quickly come across two terms, technically three, that need some explanation. The terms are Run, Search and Pounce, though the last two come as a matched pair.
<p>
The essential bit of information is that when you're on a Run, or Running, you're calling CQ and responding to other stations. You essentially sit on a frequency for a bit, start calling CQ and hope that others hear you and start to gather around to make contact with you.
<p>
The other side of that is Search and Pounce, or searching on a band for a station you want to talk to and pouncing into a gap when you can.
<p>
The two methods are mirror images of each other, so one station is generally running whilst the stations calling in are searching and pouncing.
<p>
Doing this in a contest setting requires slightly, some might say subtle, differences.
<p>
Let's investigate a contest RTTY contact. I'll simulate it between myself, VK6FLAB and Matt, VK6QS. I'll add that this is done in text in a RTTY contest, rather than voice, and, this exact exchange didn't actually happen, but for different reasons which I'll get into shortly.
<p>
It goes a little like this.
<p>
My station transmits: CQ TEST VK6FLAB VK6FLAB CQ
Matt responds: VK6QS VK6QS VK6QS
I reply: VK6QS 599 010 010
Matt replies: 599 032 032
And I finish off with: TU CQ VK6FLAB
<p>
Now this is the ideal contact, nothing extraneous, no duplication, nothing about having to repeat yourself. Mind you, if you're getting picky, you might notice that we're both sending our exchange twice, in my case 010, Matt is sending 032.
<p>
If you look closer you'll notice that all pertinent information is sent at least twice because it turns out that unlike a keyboard on a computer connected to a screen, what you type in RTTY might not actually get to the other end if you're using HF radio.
<p>
My three transmissions are the one where I call CQ, the one where I say Matt's callsign plus the exchange and the one where I say TU or Thank You, and move on. Those are the run calls.
<p>
Matt's calls consist of his callsign, and his exchange.
<p>
Note that Matt doesn't say my callsign, since I already know it and I'm running and he's searching and pouncing. He should already know who I am before he transmits. If he were to add my callsign, that would just slow things down. This is a way to keep things moving along.
<p>
In fldigi, I can program a function key that does each of those five calls. You click on a callsign, push the appropriate button and magically you're either running or pouncing. There's also a button for asking for a repeat, or "AGN?, AGN?" and one for making a log entry, which you can combine into the final thank you for running, but it's needed separately if you're pouncing.
<p>
I did say that this exchange didn't actually happen and you might well wonder why I shared it with you.
<p>
Simple. This is the bare-bones of what's required. Everything else is extra in case things break down. If there are multiple stations on the same frequency, or if your levels aren't quite right and the decoder is having a hissy fit, the human in the chain, you, need to do something manually. Very much like when you're dealing with a voice pile-up and there's this one station calling over the top of everyone else and drowning out whomever you actually want to talk to.
<p>
In a contest setting there's plenty of opportunity to do both running and pouncing and you should. If you're running on a dead band you won't know because you're getting old calling CQ, but if you're searching on that same band you'll figure out pretty quick that there's nothing happening.
<p>
Similarly, you might have a desirable callsign or location and find that running is more effective in making contacts than searching and pouncing.
<p>
Whatever mode of contesting you choose, make sure that you're flexible, since band conditions change from second to second and you will need to adapt to the winds of change. A lot like when you learn to sail and find out that you cannot just hold the helm in one spot for the entire time.
<p>
I will note that the ideal RTTY contact that I've outlined isn't universal. There's plenty of debate about the most effective way to go about things. I started with what I knew about making voice contacts, shamelessly copied the RTTY macros from another amateur and used them as a basis to learn what I needed and what I didn't, and because this was my first actual RTTY contest I watched several YouTube videos, rather than hear actual contesting stations on the air, which is something I recommend you do to get a feel for what's going on.
<p>
Contesting can be a way of life, or it can be just plain fun with learning thrown in.
<p>
I'm Onno VK6FLAB
Listen:
After channelling your RTTY ...
Foundations of Amateur Radio
<p>
It's the morning after the day before. I've been calling CQ for 24 hours and for the first time in my life after a contest I still have my voice. That in and of itself is novel. I also don't have ringing ears, that's a blessing. I have learnt heaps and had fun doing it. I made contacts and I heard stations across the globe and I did it all from the comfort of my shack chair.
<p>
Before I dig in and expand, the contest I just completed ran for 24 hours. I didn't sit at my radio for all of it, nor was my radio on for all of it. I managed to have lunch, dinner, desert, breakfast and morning tea. I snuck in a few naps and I managed to help with bringing in the shopping. My station did not transmit unattended at any time in case you're wondering.
<p>
My setup consisted of a little 11 year old netbook computer running the current version of Debian Linux and the heart of this adventure, the software called fldigi. The computer is connected to my Yaesu FT-857d via three cables, well, two and a half. A microphone and a headphone lead that combine into the data port in the back of the radio. The other cable is a USB CAT cable, a Computer Assisted Tuning cable, that plugs into the CAT port on the back of the radio. I also used an external monitor to have my main contest screen on and used it to display the main fldigi window.
<p>
My license class allows me access to a selected number of amateur bands, 80m, 40m, 15m, 10m, 2m and 70cm. I managed at least one RTTY contact on each band.
<p>
As I described previously, my radio is set to use Single Side Band and the audio from the radio is fed via the microphone socket on the computer into fldigi that processes the information. Similarly, when I transmit, the audio is generated via fldigi and leaves the computer via the headphone socket and goes into the radio as a Single Side Band audio signal.
<p>
The information in the audio is all RTTY, a digital mode that I've described previously. The software is using Audio Frequency Shift Keying, AFSK, simulating the switching between the two RTTY frequencies.
<p>
On my screen I have a waterfall display that shows all the signals that are happening within the 2.3 kHz audio stream that's coming from the radio. Fldigi is also decoding this in real-time and showing each decode as a virtual channel in a list. Click on a channel entry and your next transmission will happen at that frequency.
<p>
If you've ever used WSJT-X this will sound very familiar.
<p>
That's the mechanics of what I've been doing.
<p>
So, what did I learn in this adventure?
<p>
Well, most of Australia goes to sleep at night, at least the ones that do RTTY. I have evidence of exactly one station on-air, and that was only because they were named in the DX Cluster, which by the way this contest allows as assistance. Since then I've found logs from at least two more stations.
<p>
Local contacts did happen during the more civil hours and in total I managed ten of them. You may think that's not much for say 12 hours of work, but that's 5 Watts QRP, or low power, RTTY contacts, in an actual contest, on a new antenna, from my shack, dodging thunderstorms and learning to use filters and levels.
<p>
You might not be impressed, but I'm absolutely stoked!
<p>
During the midnight-to-dawn run, on 40m, when there were double points to be had, which I missed out on, I did manage to hear several stations across Europe, 14,000 km away, which means that I can pretty much count on global coverage with my current setup. Sadly they didn't hear me, too many competing stations, but I'm sure that with practice I'll manage to contact them too.
<p>
The software crashed once. That's not nice. It seems to have a habit of corrupting one of the preference files, which prevents it from starting up. That's also not nice. I hasten to add that I don't yet know the source of this. It may well be a dud-hard-disk sector on my ancient laptop, rather than the software, so I'm not assigning blame here.
<p>
Getting started with fldigi is an adventure. It's not point-and-click, nor plug-and-play, more like running a mainframe whilst cranking the handle, but when you get it to fly there's lots to love about this tool.
<p>
Other things that worked well were that I'd spent some preparation time getting the keyboard macros right. These are pre-defined bits of text that you send as you're calling CQ and making a contact. They're a whole topic in and of themselves, so I'll skip past the detail and just mention that I was very happy with the choices I made, gathered from years of voice-only contacts, reading RTTY contest information and looking for exchange details.
<p>
From a technical perspective, I used both contest modes, "Running" and "Search and Pounce". Running is when you call CQ, Pouncing is when they call CQ. The running was by far the most successful for me. I'm not yet sure if that was a reflection on how much I still have to learn about levels.
<p>
One thing that I can say with confidence is that there's absolutely nothing like having a wall of RTTY signals to learn how to make sure you're actually decoding something useful. I spent a good couple of the wee hours tuning my levels.
<p>
I would like to thank the stations who came back to my call and for those who tried without me noticing them.
<p>
I had a blast.
<p>
I'm Onno VK6FLAB
Listen:
Channelling RTTY
Foundations of Amateur Radio
<p>
When you start playing with radio your first interaction is likely to be voice. It could be SSB, AM, FM or something more recent like FreeDV or DMR. Your next challenge is likely going to be a digital mode like Morse Code, Radio Teletype or my recommendation for your first adventure, WSPR or Weak Signal Propagation Reporter.
<p>
I've previously discussed WSPR, today I would like to look at Radio Teletype or RTTY. It's a digital mode that allows you to send and receive free-form text. It's a mode with a long and illustrious history and it's a good next step after WSPR.
<p>
The way it works is that using an alphabet made up from two tones, information is transmitted, one character at a time at a specific speed. The code that describes the alphabet is called the Baudot code, invented by Jean-Maurice-Emile Baudot in 1849. In computing terms it's a 5-bit alphabet and in amateur radio it's traditionally sent at 45.45 baud or bits per second, in case you're wondering, named after the very same man.
<p>
The two tones have names, a Mark and a Space and they're a set distance apart. In amateur radio, they're separated by 170 Hz but there are plenty of other frequencies and speeds in use. In amateur radio the standard Mark and Space frequencies are 2125 Hz and 2295 Hz.
<p>
In a traditional RTTY capable radio the two tones are generated by transmitting a carrier whilst switching the transmitter frequency back and forth, called Frequency Shift Keying or FSK. Think of it as having a Morse key that sends dits on one frequency and dahs on another, having the radio change frequency whilst you're keying.
<p>
If you use this method to create and decode RTTY by switching between two frequencies, your radio can generally only deal with one RTTY signal at a time, just the one you're sending and just the one that's being received. Receiving is generally achieved by showing some indication on your radio how close you are to the Mark and Space frequencies that you're trying to receive and decode.
<p>
Another way to make a RTTY signal is to use sound. If you alternately whistle at 2125 Hz and 2295 Hz and you do it at 45.45 bits per second, you're also generating RTTY. This technique is called Audio Frequency Shift Keying or AFSK. Think of it as using audio to simulate the shifting of frequency by transmitting two alternating tones.
<p>
There is a fundamental difference between the two. Before I explain, permit a diversion. It's relevant, I promise.
<p>
If you've ever spoken on the radio using SSB you might have noticed that if two stations are transmitting at the same time you get both signals. With a little practice you can even understand both. This isn't true for every radio mode. If you use FM, the strongest signal wins and if you use AM, you get a garbled beep from two stations being on slightly different frequencies. As an aside, this is why aviation uses AM, so any station not transmitting can hear that two stations doubled up.
<p>
Back to RTTY.
<p>
If you use audio to generate the two RTTY carriers, rather than shift frequency, you can deal with as many as you can fit into an SSB audio signal, as long as the Mark and Space for each station are 170 Hz apart you can have as many stations as you want, overlapping even. As long as your software knows what to do with that, you'll be able to decode each one at the same time, since they're essentially multiple SSB signals being transmitted simultaneously.
<p>
An added bonus is that you don't have to invest in an SDR to play with this. You can use an analogue radio, like my FT-857d, and use software to generate an audio RTTY signal with all the benefits I've just mentioned. The magic is in the software you use to do the decoding.
<p>
As it happens, I'm about to do a contest using RTTY and I'll let you know how that goes using my radio, a computer and a piece of software called fldigi. I'll be following in the footsteps of the first ever RTTY contest, held in the last weekend of October in 1953 and organised by the RTTY Society of Southern California. In as much as I'm following in the footsteps of Morse code by spark-gap.
<p>
Wish me luck.
<p>
I'm Onno VK6FLAB
Listen:
How much do you really know about your radio?
Foundations of Amateur Radio
<p>
When I came across amateur radio nearly a decade ago I did a course, passed my test and got licensed. At that point I didn't have any equipment, didn't know about any, hadn't touched anything, other than the radio in the classroom, and had no idea about what to buy and how to choose.
<p>
So, instead I asked the friend who introduced me to the hobby, Meg, at the time VK6LUX, what radio to get. I asked her what was the second radio she ever got because I figured that I'd get very disappointed with the first one in short order. She explained that there were plenty of brands to choose from and that each had their own champions. Just like the perennial choice between Ford and Chevrolet, Apple vs Microsoft, Tea vs Coffee, you'd end up with one radio and be told by someone in a different camp that you chose the wrong one.
<p>
Her advice, which is just as solid today as it was a decade ago, was to buy something that people you knew had, so whilst you're learning there'd be someone nearby who could help. As a result I bought a Yaesu FT-857d for precisely that reason. I still have it and it has a sister, another FT-857d, bought when I needed to broadcast the local news when one of the local volunteers went on holiday.
<p>
For most beginners their journey is similar. They buy their first radio and generally that sets the tone for what comes next.
<p>
In the decade that I've been around amateur radio I've had the opportunity to play with about 30 or so different radios. For some that playing consisted of picking up the microphone and making a QSO, a contact, and not much else. For others it consisted of sitting with the radio for a full contest, 48 hours, with sporadic sleep, dealing with pile-ups where there wasn't time to breathe, but plenty of stuff to learn about filtering.
<p>
Then there were the radios that came to my shack for a visit, those at various clubs and plenty of outings where I was able to sit down and figure out how stuff works.
<p>
On the surface that's all fine and dandy. A radio is a radio, you pick up the microphone and hit go, off to the races. Then you need to figure out how to set the volume, change frequency, change bands, read what the mode is and how to change it, tune the thing, set up a filter, change the pre-amp, operate split.
<p>
For some radios this was easy, consisting of a channel button and a microphone push to talk, for others there were no buttons, just a big Ethernet socket, then there were the radios with a hundred buttons, some so small that you missed them on first glance. I've used solid-state radios, valve radios, software defined radios and virtual radios, each with their quirks and idiosyncrasies.
<p>
Every time I operate a new radio I learn something about that radio, but I also learn something about my own radio. I can begin to hear differences, observe how easy or hard it is to do something, a missing feature on my own radio, or the one I happen to be operating at the time.
<p>
In my travels I've seen plenty of radio amateurs who only have a passing understanding of their own radio, let alone any other radio.
<p>
I completely respect that this might be enough for you, but I'd like to point out that this might be a missed opportunity.
<p>
I remember vividly sitting in the middle of a bush-camp with my own radio powered by a battery connected to a hap-hazard dipole antenna strung between two trees attempting to hear a station discussing her global circumnavigation by sailing boat and being frustrated with my ability to make it work.
<p>
A friend who was sitting nearby asked if they could have a go and within seconds he was able to use the filters and offsets to make the station pop out of the noise. It's with the image of Kim VK6TQ in mind, the person who knew my radio better than I did, that I'd like to urge you to play with any radio you come across, no matter how trivial or different.
<p>
One day it will mean the difference between making a contact or not.
<p>
I'm Onno VK6FLAB
Listen:
First Digital DX contact!
Foundations of Amateur Radio
<p>
The other day day I managed my first DX contact using a new mode, FT8. It wasn't very far away, all of 2600 km or so, but it evoked memories of my first ever on-air DX contact nearly a decade ago. I should say thank you to YD3YOG for my 15m contact, fitting because my first ever was also on 15m as I recall. Unfortunately I never did log my first.
<p>
Recently a friend asked me how the two compared.
<p>
15m and logging aside, there's a lot of similarities, even though I'm a more experienced operator today when compared to when I made my first ever contact.
<p>
The preparation and the building anticipation is what made the contact all the sweeter.
<p>
A while ago I managed to connect the audio of my radio to a computer. This is pretty much the first step in starting to use digital modes. Essentially many common digital modes use an SSB transmission to generate and receive audio that in turn contains digitally encoded information.
<p>
There are hundreds of modes like this, from PSK31 to RTTY, WSPR, FT8, SSTV and many more. If you've not yet dabbled in this area, I'd recommend starting with WSJT-X. The software is so far the best tool I've found to make sure that your digital levels are correct and offers several popular modes to see how your station is operating. If you're asking for a first mode recommendation, I'd start with WSPR. Just do the receive part first, then work on from there.
<p>
There are many tutorials available, some better than others, so if the one you find doesn't float your boat, keep looking. A fly-over view is that there are several things that you need to get working and if they don't all work together, you'll get no result.
<p>
Obviously you'll need to install the software, but that's not the whole story. For the software to be able to control your radio, change bands, frequency and set-up things like split operation, you'll need to set-up the hardware to do this, in my case a CAT cable between the radio and the computer. You'll also need to set-up control software that knows how to talk to the hardware. In my case that's Hamlib on Linux, but it could be Hamlib or flrig on MacOS or something like OmniRig on your Windows machine.
<p>
The purpose is to control the radio. When you're troubleshooting, keep that in mind, hardware plus software need to work together to control the radio and this is before you actually do anything useful with the radio.
<p>
Then you need to have both hardware and software to have audio go between the computer and the radio. In my case the headphone and microphone connectors on my computer are connected to the data port on the back of the radio. If your computer doesn't have access to sockets you might need to use a USB sound-card. If your radio doesn't have an easily accessible port, you might need to have an interface.
<p>
The computer software in this case is likely setting the volume levels using the audio mixer in your operating system.
<p>
I will add that some radios have a USB socket on the back that combines both CAT control and audio. The principle though is the same. You need to make the CAT interface work, which is essentially a serial connection, and you need to make the audio work, which is essentially a sound-card.
<p>
Nothing else will make sense until you've managed to make those two work.
<p>
Then, and only then, can you try to launch something like WSJT-X, point it at the various things you've configured, then you can actually start decoding signals.
<p>
For WSJT-X to work properly, there's one more thing. An accurate clock is required. Likely you'll need to use a piece of software that knows how to synchronise with something called NTP or Network Time Protocol. The simplest is to point your clock tool at a time-server called pool.ntp.org which will get you global time coverage. Each operating system does this differently, but getting it right is essential before WSJT-X will actually make sense. You can visit time.is in a web browser to see how accurate your clock currently is.
<p>
So, get computer control of your radio working, get audio working, set the clock, then you can run WSPR, FT8, JT65 or any other mode.
<p>
I will note that I'm not attempting to give you specific computer support here, just an overview of what's needed before anything will work.
<p>
If you've been contesting then CAT control might already be operational. If you've been using a computer voice-keyer, then audio might also be ready. Depending on where you are on your digital journey, these steps might be complicated or trivial.
<p>
Once you've done all that you can start doing things like figuring out where satellites are or how to talk to the International Space Station, or use Fldigi to make a PSK31 contact or send a picture using SSTV or decode a weather fax.
<p>
When you've made that first digital DX contact, I'm sure that you too will have a sense of accomplishment!
<p>
I'm Onno VK6FLAB
Listen:
What do you talk about?
Foundations of Amateur Radio
<p>
When was the last time you told anyone anything about your hobby? What about someone who isn't also an amateur?
<p>
Have you ever considered why there is a perception that our hobby is dying, why it's running out of people, why we struggle to get air-time in mainstream media, why attracting new members is hard and why there is a very narrow range of understanding about what our hobby is, what it does and how it's relevant in the world today?
<p>
I'm a radio amateur. So are you. You might not be licensed yet, but the fact that you're here right now indicates a willingness to understand and learn, to participate and question.
<p>
Those qualities are the fundamental building blocks that make up a radio amateur.
<p>
I'm also a self-employed computer consultant, a radio broadcaster, an interviewer, a software developer, a public speaker, a blogger, author, publisher and a partner. My friends include people who are process managers, astronomers, gynaecologists, mariners, tow truck drivers, communications technicians, volunteer fire-fighters, business owners, employees, retirees, fathers, mothers, old, young and everything in between. Radio Amateurs one and all.
<p>
When you sign up to be an amateur, you don't give up all the other things you are. You don't stop being a member of society, you just add in another box marked radio amateur and you get on with your life.
<p>
If you get into this hobby you begin to realise that it sneaks into everyday life all the time. You use it to figure out how something works, or explain why it doesn't, you use it to trace a circuit or to plug in your new surround sound system. You use it to encourage curiosity in your children and to talk to your grand-children. It's not an add-on, it's part of who you are.
<p>
That's always been the case, but the perception in the general public has not been like that, it's been based around the idea that being a radio amateur is being special, being separate, being knowledgeable, studied, licensed. The reality is that the world we live in is more connected than ever and the things we once did in isolation are now part of mainstream life.
<p>
There is a perception that amateur radio is dying. Articles describe how we need to attract more people, how we need to appeal to children, how we need to recruit, become sexy or relevant. There's discussion about what's broken in the hobby, how we need to fix it.
<p>
I think that none of those things are what's in need of investigation. I think it's us. You and I. I think we need to stop being shy about being a radio amateur, about what we do and why we enjoy it; what it means and how it works.
<p>
When you talk about your activities of the day, if you made a rare contact with Tuvalu, or managed to connect your computer to your radio, or made an antenna work, or climbed on a hill or learnt Morse Code, you need to share your victories and the excitement that they bring you.
<p>
As a society we're not shy about tweeting what we had for breakfast, sharing an interesting picture or discussing an article we saw on reddit. Fundamentally what you do and who you are is worth talking about and sharing.
<p>
So, next time you talk about going camping, or discuss a barbecue you had with friends, or relate to your friends something that happened, don't be shy about your amateur radio affiliation.
<p>
It's not a secret society, it's not weird or embarrassing, it's just part of what makes you who you are.
<p>
I'm Onno VK6FLAB
Listen:
What's the point of this hobby?
Foundations of Amateur Radio
<p>
One of the recurring questions in this hobby, technically outside this hobby, asked by people who've not yet, or have only just been bitten by the bug, is: "What's the point of this hobby?"
<p>
In some ways I too have asked this question, though for me the answer came within a few months of learning that amateur radio exists. In response to others asking this I've also made meagre attempts to answer this question with varying degrees of success and satisfaction.
<p>
The typical responses are things like: there's a thousand hobbies inside amateur radio, it's about the communication, about the camaraderie, about climbing and hiking, about technology, science, physics, electronics. The truth is that this is just a fly-over view of what it means to have this as your hobby.
<p>
It occurs to me, having now been licensed for a little while, I can actually express a little more clearly what this hobby has given me.
<p>
At a basic level, I now know what the front of a TV aerial is and how Wi-Fi is attenuated by walls, how line of sight works and why you can talk to the International Space Station with a hand-held radio. I've learnt about sunrise and sunset and how they affect propagation, the grey line and how the ionosphere is broken into layers that are affected by solar radiation. I've learnt about sunspots and how they change over time, that there are cycles, that there is a thing called the Maunder Minimum and that propagation is a fickle beast. I've learnt about the Ionospheric Prediction Service and about band planning in contests, about dealing with pile-ups and making contacts, about voice-keyers and computer controlled radios, about contesting software and logging, about contest scoring and contest rules.
<p>
I've learnt about gain and about loss, about how 75 Ohm coax differs from 50 Ohm coax, how connectors work, about soldering and crimping, how to use a crimper and what connectors to use with which coax. I've learnt about path-loss and about bouncing signals off the moon, about Sagittarius A*, a bright and very compact astronomical radio source at the centre of the Milky Way and about inclination and ascension, about galactic coordinates and observation windows, about programming in Python and the astropy library.
<p>
I've learnt about how radio signals are used to encode information, the seemingly infinite supply of digital modes and how a radio signal can be described in three dimensions. I've learnt how maths can describe amplitude modulation and how side-bands can be described, about signal to noise ratios and decibels.
<p>
I've experienced the joys of making a rare contact, to places like Amsterdam Island, Prince Edward & Marion Island, Heard Island, Micronesia, Cuba, Kiribati, and many more. I've learnt more about geography, about maidenhead locators, learnt new phrases and started learning new languages.
<p>
I've gone out camping more times than I can count, spent nights under the stars making contacts across the globe. I've set-up my station in parks and on peaks across the country, made life-long friends locally and abroad, tested my patience and my endurance.
<p>
I've learnt about the pioneers and inventors who came before me, about their successes and failures, their enduring legacies and their inventiveness. I've gained insight into Apollo radio communications and distance measuring, global positioning before there was GPS, about satellite dishes and radio during disasters, about emergency communications and temporary set-ups with just enough to get the job done.
<p>
I've written software, made charts, learnt how to use GNUPlot, written articles, recorded podcasts, interviewed amateurs, published books, produced, presented and transmitted amateur news broadcasts, built amateur radio websites, chaired meetings, raised funds, contributed to club committees and helped as I was able.
<p>
I've helped organise a national amateur radio conference, learnt how to teach others and created a weekly radio net for new and returning amateurs. I've acted as a point of contact, offered life advice and acted as a shoulder to cry on when the going got tough for some of my fellow amateurs.
<p>
I've built more, tested more, explored more, learnt more and done more in the past decade than I have in the 40 years before that.
<p>
When I look back over the 472 podcast episodes I've written so-far, that massive list is only just scratching the surface and it only just begins to describe how deeply affected I've been by this hobby. It only barely describes the width and depth of this hobby and I've only been here for a little while.
<p>
I must point out that I did all these things because I could, because I had radio amateur friends who prodded and poked, who helped and asked, who gave and received. My exposure over this decade was only possible because there are others who share my interests and stopped to take a moment to express that.
<p>
Next time you're asked about how amateur radio is relevant, how it relates to the world, how it affects you and your life, what it's given you, or what you can gain from it, consider, even just for a moment, just how much is possible within this massive hobby.
<p>
I'm Onno VK6FLAB
Listen:
Homebrew radio for the 21st Century
Foundations of Amateur Radio
<p>
The hobby of Amateur Radio is essentially one of experimentation. Within our community we endlessly build things, from amplifiers to Yagis and every letter of the alphabet in between. With every experiment we grow the amateur radio sphere of influence just a little bit.
<p>
As our hobby is evolving into Software Defined Radio, or SDR, the homebrew aspect of our community is also changing bit by bit and as a result, homebrew today is just as likely to be based on software as it is in hardware.
<p>
Unlike the physical world where you need to source and buy components, design a circuit, build it, test it and then put it in a box, in the software realm you can get started with the computer that is more than likely within reach right now.
<p>
Recently I took delivery of a new SDR, an ADALM Pluto. It's essentially a Linux computer, FPGA and transmit capable SDR in a small box. I bought it specifically for the purpose of experimentation.
<p>
One of the first things I did with this device was install an existing piece of software called dump1090. The tool listens to 1090 MHz and decodes Mode S transponders, used by aviation to report aircraft information in real-time.
<p>
Originally written by Salvatore Sanfilippo in 2012 for the RTL-SDR dongle, it was patched by several people and in 2017 it was updated by Jiang Wei to support the Pluto SDR. My contribution to the project is minor. I've updated the on-board web-server to use Open Street Map and a few other cosmetic changes.
<p>
For me it was a "Hello World" project, something that's the software equivalent of warming up your soldering iron and pre-tinning the wire you're about to use.
<p>
The tools to do this is what I want to discuss.
<p>
When you look at the software that underlies much of the SDR world, the digital modes, logging, contesting, even the software inside tools like the Nano-VNA, much of it is open source. That means that as a curious amateur you can have access to the underlying equivalent of the circuit diagram. As you can with a soldering iron, a scribe and wire, you can patch or update a circuit. In the software realm you can do the same once you have access to the source code.
<p>
The tools you're going to get in touch with are text editors, compilers, libraries and configuration files. If that's not your thing, I appreciate that, but if it sparks your interest, you'll open the door into a brand new world of software development where you can determine how a mode works or what it supports or how it interacts with your radio or testing gear.
<p>
When you jump in, likely feet first, you're going to make mistakes and lose hair and sleep and you'll be shaking your virtual or physical fist at the person who came before you, but then that's the world of experimentation, so likely you'll already have that down pat.
<p>
You'll likely play with different tools that require different versions, often installed side-by-side, much to your chagrin when you learn that it just won't work. Not to mention that removal of the offending tool often leaves interfering cruft behind, not unlike unsightly and short-circuiting blobs of solder.
<p>
I'm here to introduce you, albeit briefly, to a tool that will take much of that pain away. The free tool is called Docker. It has got little in the way of visibility in the amateur radio world, but in the software development world it's pretty much old hat.
<p>
Essentially the idea is that you can install stuff into a so called disposable container so you can have your copy of dump1090 installed in one container and your copy of codec2 in another, a copy of rtl-sdr in a third container, all working independently from each other, without needing to complicate things with multiple computers or virtual machines. If a developer uses Debian, another uses Ubuntu and a third uses Red Hat, you can run these side-by-side without any issue. If they need an ancient version of something, that too is handled without a problem. Make a mistake, destroy the container and start again, fresh.
<p>
Docker is a tool that allows you to build an environment on Linux, MacOS and Windows, as well as the Raspberry Pi, that acts and behaves in many ways like a virtual machine. In all the ways that you're likely to use it, at least initially, it's indistinguishable. What that means is that the operating system, the compiler and the libraries that you need for one tool won't affect those needed for another tool.
<p>
The best part of this is that you can build on a massive library of pre-existing Docker containers and use files that describe how to build and compile tools like dump1090.
<p>
If you look for my callsign vk6flab on github.com, you'll find my version of dump1090 and you'll find a Dockerfile that describes how I built it. The project contains all the bits you'll need to get started with your own version of dump1090, or some other project that tickles your fancy.
<p>
Every time you build something, the amateur radio sphere of influence grows just that little bit.
<p>
I'm Onno VK6FLAB
Listen:
What is a repeater offset and how does it work?
Foundations of Amateur Radio
<p>
Every week I run a net for new and returning amateurs. A variety of people join in with varying degrees of skill, knowledge and number of birthdays.
<p>
One of the regular things I say during that net is that if I'm not acknowledging you, it's because I cannot hear you. I then start a spiel about repeater offsets and give some examples, but what is it really and how does it work?
<p>
As you might recall, a repeater is a radio, generally located somewhere useful, like on a hill or tall building, that offers the ability to talk to other amateurs who are not within range of your radio.
<p>
For bands like 2m, 70cm and 23cm, generally speaking, contacts are line-of-sight. If you're standing on a hill, you can talk to more people because your line of sight is further away.
<p>
This is also why you can talk to the International Space Station with a hand-held, since it's in your line-of-sight, at least some of the time.
<p>
A repeater acts as a line-of-sight extender. If it can see both you and another station, it can act as a bridge between you.
<p>
How it does this is pretty simple. A repeater listens to your signal and transmits that to the other station. It uses two separate frequencies to make this happen. A receive and a transmit frequency, or more precisely an input and an output frequency. To remember which is which, you can think of a repeater as a giant megaphone, you talk into it and sound comes out. Said differently, think of a repeater as a device that takes an input from one station and makes an output for everyone to listen to.
<p>
To actually use a repeater, your radio needs to be setup to transmit on the repeater input and it needs to receive on the repeater output. This means that when you transmit, the repeater can hear you and when you're listening, you can hear the repeater.
<p>
To achieve this, you can set your radio up using repeater mode. It uses a thing called an offset to set the difference between the input and output frequencies.
<p>
To find out what the offset is, you take the repeater input frequency and subtract the repeater output. If you've set-up your radio correctly you're tuned and listening to the repeater output. When you hit the Push to Talk or PTT, you'll transmit on the input frequency and when you let go, you're back to receiving on the output frequency.
<p>
One final roadblock might be that your local repeater has a tone lock. If it does, the repeater will ignore you even if you have all the frequencies correct. This tone is generally published by the repeater owner or your local regulator. You can also check a website called repeaterbook.com to see many of the world's repeaters and their specific settings.
<p>
Now, I should point out that while repeater offsets are standardised, they're not the same across bands, across the world, or even within a country or city. Depending on where you are, what the density of repeaters is and what band you're on, the offset number and direction will change.
<p>
It's even possible that you have a variety of offsets on the same band in the same city. This means that you cannot just pick a standard offset for your radio but most modern radios will have a method to deal with this.
<p>
It's easy to get this wrong.
<p>
Setting up your radio for using a repeater is deciptively simple. Three things to look out for when it's not working. You have the input and output reversed, the offset is wrong, or there's a tone blocking your transmission.
<p>
I'm Onno VK6FLAB
Listen:
Your antenna is a filter (of sorts).
Foundations of Amateur Radio
<p>
The single most discussed topic in amateur radio is that of antenna design, that and medical procedures on 80m, but I kid. Previously I've discussed the notion that all frequencies are on-air all the time and that your traditional radio uses much of its electronic circuitry to filter out all the things you don't want to hear.
<p>
Parallel to that is the concept that you tune your antenna to be resonant on a particular band or frequency. As amateurs we might look for a wide-band antenna that makes it possible to use our radio across several bands. We often construct our antennas to be multiple harmonics of a band so we can have access to more spectrum without needing more physical antennas.
<p>
None of this is new and as an amateur you'll likely spend the rest of your days improving your antenna situation, or at least talking about it, if not outright bemoaning the lack of antenna space, family approval, budget or some other excuse.
<p>
As I started my journey into Software Defined Radio a new idea occurred to me. If an antenna is a resonant circuit, could you think of your antenna as a filter, as-in, something that leaves out the things you don't care about?
<p>
In and of itself I'm sure I'm not the first to consider this notion, but the idea means that you essentially turn your idea of an antenna on its head, from something that receives to something that rejects.
<p>
Consider for example the small transmitting loop antenna, often also called a magnetic loop antenna. It's got one characteristic that isn't often considered a benefit, it has something called a High-Q, or a high Quality Factor. The higher the Q, the narrower the bandwidth.
<p>
I should digress here for a moment. Q is a number. Big number means narrow bandwidth, little number means wide bandwidth. It's easy to calculate. If you look at an SWR plot of an antenna you'll see a curve where the bottom of the curve is the lowest SWR of your antenna, that's the centre frequency. You'll also see two points on the same curve where the SWR hits 2:1. If you take the centre frequency and divide that by the difference between the two edge frequencies, you'll have the Q of that antenna.
<p>
Using numbers, consider an antenna that's got an SWR below 2 between say 7 MHz and 7.2 MHz, a bandwidth of 200 kHz, you'd have a centre frequency of 7.1 MHz. The Q of that antenna would be 7100 divided by 200 or a Q of 35.5
<p>
If you had an antenna that had a bandwidth of 5 kHz at 7.1 MHz, it would have a Q of 1420.
<p>
And just to wrap that up. This is helpful because just comparing bandwidth on different antennas doesn't tell you enough. Is an antenna that has 400 kHz bandwidth on 20m more or less selective than an antenna with 200 kHz bandwidth on 40m, what about 100 kHz on 80m?
<p>
Back to the small transmitting loop antenna or mag-loop. If you're using such an antenna on an amateur band like say the 40m band, you'll likely have to re-tune your antenna every time you even think about changing frequency. I've had the frustration of using a manual version of such an antenna and it can wear thin very quickly.
<p>
I'm bringing this up because it can also be a benefit.
<p>
Imagine that you need to make a contact on a busy band during a contest. Often you'll find yourself setting up the filters on your radio, trying hard to remove all the extraneous noise that comes from strong signals nearby.
<p>
What if your antenna could help with that?
<p>
What if you thought of your antenna as a pre-filter, something that makes the job of extracting just that signal from the bit of spectrum you're interested in?
<p>
My point is this.
<p>
We're talking about an antenna that from one perspective can be a pain to use, requiring constant retuning, constant adjustment, just to get on the air and make noise.
<p>
From another perspective, that very same antenna is a way to filter out the things you don't want to hear and extract the signal you care about.
<p>
How you approach this depends on your perspective and just considering your antenna as a filter might help you see another side of your antenna system that you hadn't considered before.
<p>
How you use this is entirely up to you. For my money, I'll be doing more experiments.
<p>
I'm Onno VK6FLAB
Listen:
If you WSPR and nobody hears you ...
Foundations of Amateur Radio
<p>
The day came to pass when all my set-up and configuration was going to culminate in the moment of truth when I enabled TX on my WSPR mode station. Before I tell you of my experience, I should give you a little bit of background.
<p>
A few weeks ago I managed to erect a HF vertical at my home or QTH. That in and of itself was news worthy, well at least to me it was, since it was the first time since I became licensed in 2010 that I had actual real all-band HF capability at home. Last weekend I ran some RG6, yes, 72 Ohm Quad Shield, low-loss coaxial cable, from my antenna, through the roof, into my shack.
<p>
I was thrilled.
<p>
Immediately set about getting my HF station up and running. This involved installing WSJT-X, a tool that allows you to do weak signal work, perfect for when you're a low power or QRP station like me. I've previously reported using WSPR, Weak Signal Propagation Reporter on a Raspberry Pi and a dongle, but this time I was using my Yaesu FT-857d.
<p>
Reports were coming in thick and fast. Managed to hear stations on all the bands I'm allowed on, 80m, 40m, 15m, 10m, 2m and 70cm. Managed to make it report online and update the various maps around the place.
<p>
Brilliant!
<p>
Now I wanted to do the next thing. Transmit and see who could hear me and how far my beautiful callsign might travel on 5 Watts.
<p>
So, after some abortive attempts, I configured the levels correctly, made sure that my antenna coupler, an SG-237, was tuned and hit "Enable TX" on the screen of my computer.
<p>
Dutifully my computer did what was expected, turned on the transmitter and happily made the fan run on my radio for two minutes at a time. I tried 80m, 40m and 15m. All worked swimmingly.
<p>
Then I looked on the map to see who had heard me.
<p>
Nobody. Nothing. Nada. Niets en niemand.
<p>
I could hear N8VIM using 5 Watts, 18649 km away, but nobody could hear me, not even the station VK6CQ who is 9 km from me.
<p>
So, what's going on?
<p>
Turns out that I'm not using a "standard" callsign. That's right, my VK6FLAB, authorised by the World Radiocommunication Conference 2003, implemented by the Australian regulator, the ACMA in 2005 and issued to me in 2010 isn't a standard callsign.
<p>
Seems that the deal-breaker is the four letter suffix, FLAB, that's killing my attempts at making contact.
<p>
Now I know that there are moves under way, not quite sure what stage they're at, to allow Australian amateurs to apply for any three-letter suffix and keep that regardless of their license level, but that to me doesn't really solve the underlying issue, where a perfectly legal callsign isn't allowed to be used by one of the most popular modes today.
<p>
I've lodged a bug report on the WSJT-X mailing list, but to accommodate this callsign will probably require a fundamental change in the way the WSPR mode and likely several other JT modes will work, not to mention the databases, the maps, API calls and other fun things like logging.
<p>
Technically I could have figured this out back in September 2019 when I was first allowed to use digital modes with my license, but I didn't have an antenna then.
<p>
In case you're wondering. I also investigated using a so-called extended, or type-2 message, but that allows for an add-on prefix that can be up to three alphanumeric characters or an add-on suffix that can be a single letter or one or two digits.
<p>
I could use something like VK6FLA/B, but I'm sure that the owner of VK6FLA would be upset and using VK6/F0LAB might have a French amateur yell Merde! at me when they spot their callsign being transmitted from VK6.
<p>
One suggestion was to upgrade my license.
<p>
What's the fun in that?
<p>
I'm Onno VK6FLAB
Listen:
Using something for an unexpected purpose can give you many great rewards.
Foundations of Amateur Radio
<p>
The other day I was getting ready to go out when rain started pelting down. Not unexpected in this part of the world at this time of year but inconvenient for my plans.
<p>
I didn't particularly want to carry an umbrella and the thought of wearing a rain hood brought back memories of water trickling down my back.
<p>
For reasons I'm not quite sure of, my eye fell on my hat on its hook at the door. The hat I wear in the heat of summer to keep my brain from frying, the hat I use whilst camping with my amateur radio friends, the hat I've worn whilst loading massive hay bales with a tractor and the hat I've worn swimming in the Ord River - well, a descendent, third generation if I remember correctly. I shook my head in disbelief, after donning my raincoat, put my trusty Akubra Territory on my head and stepped out into the rain. Perfect. Kept me dry, kept my glasses clear and no drips down my back.
<p>
You may well wonder what this has to do with radio and that's a fair question. I will preface this with a disclaimer that you might not have this set-up in your shack just now, but perhaps it will inspire you to get started.
<p>
I've been talking a lot about Software Defined Radio, and I do believe that it represents the future for our hobby, but that doesn't mean that my traditional radio, in my case a Yaesu FT-857d, is headed for the scrap heap just yet.
<p>
As you might know, with some preparation you can connect your radio to a computer and control it. You can also connect both the send and receive audio to a computer using a variety of techniques which I probably should get into at some point.
<p>
Assuming that you have, and I realise you might not yet have done this, but assuming for a moment that you have made this all work, you can use this to do things like JT65, FT8, PSK31, SSTV and hundreds of other modes.
<p>
One thing I did during the week was use this set-up to listen to noise. Seriously, that's what I did. I picked a spot on the band with nothing but noise. No discernible signal and fired up the application WSJT-X, it's the tool you use for many weak signal modes. As an aside, as a tool, it is also helpful in getting your digital mode levels set correctly.
<p>
One of the windows in WSJT-X is the waterfall and spectrum display. On it you can see the signal as it is right now and how it's been in the past.
<p>
If you turn on one of the filters on your radio, you can see the display change. You can literally see what gets filtered out. On my radio I've got the standard filter, as well as a 2 kHz and a 300 Hz Collins filter. Using this technique, you can specifically see what each filter does. If I turn on the built-in Digital Signal Processor, the DSP, I can see what the adjustments do, as well as the impact of the mode on the filter. And how the various settings interact.
<p>
For example, until I saw this display, I didn't know what the "DSP HPF CUTOFF" and "DSP LPF CUTOFF" specifically did and how they interacted with the other filters. Similarly what "DSP BPF WIDTH" did and how.
<p>
I also didn't know that even if you set both the high and low pass filter frequencies to the same value, you still have a usable filter, even if you might think that nothing could get through.
<p>
Now I do realise that your radio may not have those specific settings, but I am confident that if you pick a spot on the band, set up a frequency display and waterfall, you'll discover things about your radio that you hadn't before. I also realise that you can hear some of this by just playing with filters, but seeing it on the scope adds a whole other dimension to the experience. Just one example is to see how a narrow filter interacts with the in-built DSP, something that's difficult to hear, but easy to see.
<p>
If you have a Morse beacon to hand, you can also see how various frequency shifts work and the impact of selecting filters in relation to that signal. No need to just listen to the beacon with just CW mode either. Have a look at it using SSB.
<p>
Using something for an unexpected purpose can give you many great rewards. As for the hat, really, I hadn't used my hat to ward off the rain until then; you live and learn.
<p>
What have you discovered recently?
<p>
I'm Onno VK6FLAB
Listen:
How to pick a field operating position?
Foundations of Amateur Radio
<p>
Much of the operation that I've done as a radio amateur is conducted in the field. That is, I tend to either drive my car to a location, or go out with friends and set-up camp to play. After you do this for a while you start to notice the things that you look for in an operating position.
<p>
The very first one is accessibility. That is, how easy is it to get there? It's fine coming up with the ultimate location, but if it's an hour's drive away and you've only got an hour to play, you'll spend all your time getting there and you'll be home late.
<p>
By contrast, for field days lasting several nights, I've regularly driven more than a hundred kilometres to find the spot, sometime much more than that. The point is that the accessibility changes depending on your available time. The journey to the location can be just as much fun as the destination itself.
<p>
How long you plan to be there will determine what antennas you might want to set-up. If you're there for an hour, you'll likely use a vertical on your car. If you're there for the weekend, your antenna farm will be determined by how much wire you brought and what you can hang it off.
<p>
Hanging antennas is the next thing. You can bring your own poles, but for height, nothing beats a solid tree. The taller the better. More taller, more better. If you have several to choose from, you get to play with all manner of fun stuff. For one antenna contraption we had three trees that we ran a wire between. They were roughly spaced in a triangle about 200 meters apart from each other. As I recall, the antenna we built, a massive V-beam managed to talk to Europe for most of the weekend.
<p>
For another adventure a simple G5RV dipole was hoisted high into the trees. Another was accomplished by strapping a pole to a fence and setting up an inverted-V antenna. Recently we set-up an antenna that was nothing more than a wire running over the ground.
<p>
So, generally speaking height is good. You can cheat by having a low tree and a hill. Or a fence and a pole, or a gazebo and tent-pegs. What ever you can do to attach an antenna to will work to some degree. Which reminds me, if your hill is tall enough, it's likely to have a communications tower on it for someone, if not everyone. They're not the end of the world, but they can cause havoc with noise. Depends entirely on what the communication structure is used for. Bear in mind, some of these sites have noisy solar panel inverters or generators, so that too needs to be taken into consideration.
<p>
Another factor in picking a location involves water. Setting up a vertical on a jetty is gold. I've made many long-distance contacts using a vertical with a ground wire running into the ocean. Note that you don't have to actually get wet. Being near the ocean is often enough. I've had plenty of success from a beach car-park from a vertical on my car.
<p>
In general, man-made objects such as houses, factories, other cars, power lines, generators, boats, camping grounds with solar panels and plenty more are often bad news for HF communications. The biggest disappointment happens when you take the time to go to a site, set up camp, build your antennas, turn on the radio and all you hear is the noise from a nearby source of interference.
<p>
That said, you don't need to travel to the ends of the earth either. 15 minutes from my house is a lake with a park. There's a car park which on occasion attracts a motor home with a solar panel, but by enlarge it's a local park with people going for a walk. From a radio perspective, despite homes, businesses, schools and cars nearby, the place is heaven. It's quiet, it has shade, running water, fence posts and I regularly make contacts from there, right in the middle of the city.
<p>
That brings me to another aspect. Creature comforts.
<p>
Setting up near a busy road isn't fun. Neither is sitting in your car without shade. Having amenities within reasonable distance helps. For example, recently for a field day we set-up within 10 minutes drive from a regional centre. Didn't even notice it was there, happily dropped in for shopping and a meal. Some beers might have been consumed.
<p>
That same site also had high voltage power lines near our location. The only difference was that our site was above the power lines at the top of a hill, so we never even noticed them.
<p>
Finally, some of this is all about picking a camp-site that's suitable for radio, rather than a radio site that will handle camping. You get better at it the more you do it. If you check back after the adventure, you'll learn some stuff as well, so don't be shy to discuss your experience with your friends.
<p>
What ever you do, practice makes perfect.
<p>
I'm Onno VK6FLAB
Listen:
The humble coaxial cable
Foundations of Amateur Radio
<p>
If you've ever used a spray can of WD-40, you might have wondered what the name means. It stands for "Water Displacement, 40th formula". In my time as a radio amateur I'd never stopped to think what the RG in RG-58 stood for. Turns out that it too has a meaning, "Radio Guide", though I have found some interesting alternative descriptions where the G stood for Government.
<p>
This radio guide, really a transmission line, gets a signal from point A to point B. Depending on how you construct that transmission line determines what you'll get at the other end.
<p>
Coaxial cable or coax is a length of cable made from several components. There's the outer layer or jacket, that protects the cable from electrical shorting, U/V deterioration and water ingress which causes all manner of problems. Inside that is an electrically conductive shield that forms one half of the transmission line, inside that is a dielectric, essentially a separator or insulator between the shield and the inner most, or central conductor, the core.
<p>
Each of these components can change. On the outside the first thing you might notice is the thickness of the cable. The next thing you might observe is how flexible it is. Below the outer surface other things can also be altered. For example, the core could be a solid copper wire, or it could be strands of copper. It could be aluminium, silver or even steel. It might not even be wire. Some coax like Heliax, used in broadcasting, uses a central conductive tube as the core with air as the insulator between the core and the shield.
<p>
The dielectric that separates the core from the shield can be made from different materials such as plastics, air and even inert gas such as nitrogen and it comes in varying thickness. Similarly the shield can vary in thickness, material and construction. There are also variations that have multiple levels of shielding, such as for example Quad Shield RG-6, common in satellite television and internet connections that has four layers of shielding.
<p>
Other aspects might not be nearly as obvious. If you're running coax down a power line it will need physical strength. If you're burying it in the ground it will need to be protected from water ingress. Temperature and heat dissipation are also considerations and if you're using the coax in a nuclear reactor, its ability to deal with radiation. More commonly if you need to run the coax around a corner, how tight it can be bent is another consideration.
<p>
As the materials and dimensions are changed, the characteristics of the coax changes. Each of these are documented and standardised.
<p>
The standardisation is both a blessing and a curse. So many options and so much to choose from.
<p>
For example, if you compare RG-58 to RG-59 they look pretty similar. If you cut into them you'll notice that they're made from similar materials. If you put them side-by-side, you'll notice that RG-59 is thicker, by about 20%, conversely the core for RG-59 is thinner by about 20%, this also means that the dielectric is about 30% different in thickness. As a consequence, connectors for one might fit on the other, but rarely work well.
<p>
These variations mean that while both types of coax are common and priced similarly, they're not interchangeable. RG-59 used to be common in satellite TV installations and is still used in CCTV, whilst RG-58 is common in radio communications.
<p>
If you made the decision to actually go out and buy RG-58, you'll come across many variations indicated by extra letters. For example, BC means Bare Copper and TC means Tinned Copper.
<p>
The final piece of the puzzle in this tangled offering of transmission line is that each manufacturer has their own way of doing and naming things in pursuit of market share. For example, the coax I installed recently is known as LMR-400, CNT-400, WBC-400 and several others.
<p>
If the performance of your coax actually matters that much, I'd recommend that you spend some time looking at your options before handing over any money.
<p>
All that behind the name of a piece of coax that runs between your radio and antenna.
<p>
I'm Onno VK6FLAB
Listen:
The antenna and coax you use matter.
Foundations of Amateur Radio
<p>
During the week I climbed on my roof and installed a base antenna for the 2m and 70cm band. The antenna is a Diamond X-300N. It's 3 meters tall, has a gain of 6.5 dB on 2m and 9 dB on 70cm. I've owned it for just under eight years and this week I finally took it out of the box and installed it. I know, I know, in my defence, you shouldn't rush these things.
<p>
Truth is, until this week I really didn't have a realistic way of installing it. Several factors needed to come together. Some of them trivial, others less so. In the end, the antenna is now installed on my roof, connected via coax through my roof to my radio.
<p>
Now before we get all excited about what that means, let's compare my previous outdoor setting to the current one.
<p>
Today I'm using LMR-400 coax, 30 meters of it. Previously I used RG-58, but only 20 meters of it.
<p>
From a coax perspective, even though I increased the length by 30%, my loss actually went down, on 70cm it went down by over 4 dB. If you recall, 3 dB loss is the same as losing half your signal, so before my 5 Watts even got to the antenna, I'd already lost more than half of it using RG-58.
<p>
I will mention right now that the numbers I'm giving here are purposefully not exact. There's no point. Your situation and mine are not the same, and my two installations are barely equivalent, so actual numbers don't help you.
<p>
The point I'm making is that the type of coax you use to feed your antenna can make a massive difference. In my case that difference means that half of my 5 Watts never even made it to the antenna.
<p>
In addition to this the two antennas are different. Not by much, but enough to make a difference. As icing on the cake the new antenna is longer by a third, so my new antenna has a better horizon, it's higher off the ground, even if it's installed at a similar height.
<p>
You might recall that loss and gain are dependent on frequency, so any calculation needs to be done for each band you're going to use. In my case I had to do this twice, once for the 2m band and once for the 70cm band.
<p>
I should also mention that depending on the SWR of your antenna, the losses also change, but let's not go there today.
<p>
If you want to actually figure out what this means for your station, the calculation goes a little like this.
<p>
Take the power output from your radio, subtract the coax loss and add the antenna gain. The end result is a number that represents the gain - or loss - from the entire system. If coax loss and antenna gain are the same, you're not losing anything, but you're also not gaining anything.
<p>
The reward for the aches and pains from climbing on and in my roof are represented by the fact that now my 5 Watt signal on 2m effectively became 10 Watts. On 70cm it became 13 Watts.
<p>
With the added height and gain in addition to being able to hit all the local repeaters, I can now hear the local beacon and I've successfully decoded the JT4 and JT65 messages that the beacon spits out.
<p>
It's only been a week, but it's already made a massive difference.
<p>
No doubt my on-air experience will also benefit from this adventure.
<p>
Unfortunately, to do this for yourself is not quite as simple as giving you a link and punching in the numbers. I won't make any promises I cannot keep, but I am looking into it.
<p>
I'm Onno VK6FLAB
Listen:
Buying and using pre-loved equipment
Foundations of Amateur Radio
<p>
The other day I received an email from Colin VK2JCC who mentioned that he was a keen home brewer and he was interested in a discussion about using ex-military gear in amateur radio. If you want to see his beautiful rig, check out Colin's Clansman PRC 320 Radio, does 2 to 30 MHz at 3 or 30 Watts. Look for his callsign and you'll also find a video of him calling CQ.
<p>
Colin also shared his efforts for the construction of a Ground Tuning Unit which started a whole different exploration, but I'll leave that for another day.
<p>
Back to the topic at hand, ex-military gear in our hobby. My initial thoughts on the subject were predictable: "What on earth do I know about this and do I have anything useful to contribute on the matter?"
<p>
It turns out that this isn't something new to me. You might recall that I'm an IT professional in my non-amateur life. In that role you'll likely never see me buying second hand or refurbished gear, unless I installed it myself and was the person responsible for its maintenance.
<p>
This same mindset prevails within my hobby. Although I am the owner of several pieces of pre-loved equipment, it arrived either because I knew the previous owner and where they live, or because it arrived unencumbered at my door.
<p>
I go to hamfests and look askance at the gear on offer. I'll buy connectors, a tower, but not so much anything in the way of electronics. I asked around and I'm not alone in this. Many of my peers have the same view. Why pay good money for something that has been abused?
<p>
It occurred to me, that this mindset is based on the idea that something can go wrong because the equipment has been invisibly damaged. Of course that is possible. However, on reflection, the reality is likely different.
<p>
In my professional life I've seen plenty of badly maltreated equipment. I remember being called out to a faulty computer that sat on the ground in the office in a car mechanics workshop. The computer, used for accounting, would on warm days just stop. On opening it up, in 2006, I found a motherboard with a Pentium processor on board. It was untouched from when it had been built in around 1994. The CPU fan was no longer moving and the amount of caked on dust - complete with microscopic motor oil - had formed a solid cake around the cooling fins. After removing the dirt, the fan spun back into life and the computer was once again rock-solid.
<p>
That is the definition of abused electronics.
<p>
Yes, in case you're wondering, I did recommend replacing the computer, but out in the back roads of Australia, that's easier said than done.
<p>
Story aside, I came to the conclusion that while abuse might reduce the circuit life from a millennium down to a century, that was unlikely to happen in my lifetime.
<p>
Back to the ex-military gear.
<p>
Based on Colin's comments, his historic radio, and my insights into the scale of abuse and their impact, I'm more inclined today than I was yesterday to investigate.
<p>
I will note that I'm spoilt for choice. I can pretty much buy off the shelf any gadget required, limited by my imagination and my budget, but that wasn't true for several of my amateur friends. I know of several modifications of aviation and military rigs, born from necessity, that eventually made it into amateur radio and come to think of it, there's not much difference from me adding a serial interface to my Commodore VIC 20 back in the 1980's.
<p>
Before I start shopping for radios that glow in the dark, there is another consideration. I did the same with computers over 20 years ago. I ended up with about a dozen of them in my office. Today that's replaced by a single one that runs as many virtual computers as I need.
<p>
In radio terms, do I fill my shack with boxes, or should I spend my efforts on getting an RF signal into a black box with SDR written on the side? It's hard to know what the differences are without seeing both sides of the equation, but I'm sure that at my next hamfest I'll be looking around with different coloured glasses.
<p>
Thank you to Colin VK2JCC for asking the question and showing his toys.
<p>
I'm Onno VK6FLAB
Listen:
How much is a bit worth?
Foundations of Amateur Radio
<p>
During the week I finally made the decision to purchase my first software defined transmit capable radio. It wasn't an easy choice for me, given that the range of options vary in price from "not much" to "more than my car is worth" and an infinite number of choices between those.
<p>
One of the considerations, other than price, was a thing called bit-depth. In the past I've spoken about how an analogue to digital converter or ADC uses bits to represent a radio signal. In short, a voltage coming from an antenna is represented as a digital value inside the radio. No signal represents a value of zero and maximum signal represents the maximum value that fits into the decoder. A concrete example might be an 8-bit ADC which can represent 256 different values.
<p>
If you look at the choices available to you, you'll see that there are 8-bit radios, 12-bit ones, 16-bit, 18-bit and 24-bit radios. On the face of it you could just say, more bits is better, but how much better?
<p>
For example, an ANAN-10 and a FLEX-3000 radio, both costing about the same, have a different ADC. The ANAN is a 16-bit device and the FLEX is a 24-bit device. At the other end, a HackRF One is an 8-bit device and costs twice as much as an ADALM Pluto that's a 12-bit device.
<p>
How do you choose and what are you choosing?
<p>
Essentially you're choosing something called dynamic range. Think of it as the range of signal strengths that you can represent using a number of bits.
<p>
As it happens there's a formula for that. It's 20 times the log 10 of 2 to the power of the number of bits times the square root of 3 divided by 2 and it represents decibels relative to full scale or dBFS.
<p>
In more recognisable terms, it comes down to a bit being worth 6 dB of range. A good approximation is the number of bits times six plus two.
<p>
For example, a 6-bit SDR will have a dynamic range of 6 times 6 bits is 36, plus 2 makes 38 dB of range. An 8-bit SDR has 6 times 8 bits is 48 plus 2 makes 50 dB of dynamic range.
<p>
I'm using rounded off numbers here but it gives you a pretty accurate sense of scale. Six times the bits plus 2 works until about 36-bits and then it's off by one dB, until we hit 85-bits - which we won't likely be able to buy at the local ham store for a little while yet - and then it'll be off by 2 dB.
<p>
Another way to think of dynamic range is to think of it as the difference between the weakest signal you can measure and the strongest signal. Given your SDR is going to be using a whole chunk of radio spectrum, you likely will have to deal with your local broadcast stations as well as that QRP signal you want to decipher, so more dynamic range is better.
<p>
Let's give this some context. The Australian Broadcasting Corporation, the ABC, has a local AM station on 720 kHz that has a transmitter with an EIRP of just under 155 kilowatts. My QRP station uses 5 watts. My signal is 45 dB weaker than that local transmitter.
<p>
This means that in order for an SDR to be able detect my signal in comparison to the broadcast station, it would need to have a range of 45 dB or 45 less 2 is 43 divided by 6 is 8 bits range at a minimum.
<p>
Now this isn't precise or complete, but it should give you some sense of scale.
<p>
In this example, the amplitude range of my 5 watt signal is represented by a digital range of 1 and the broadcast transmitter is represented by a range of 255 values.
<p>
That means that the best you could hope for in decoding my signal would be if I was transmitting Morse, the absence or presence of my signal would make the value representing my signal go from 0 to 1.
<p>
As you might imagine, this is not suitable to decode something more complex like SSB. My Morse signal is also right at the noise floor, so it might not even be detectable at all.
<p>
Similarly, in the absence of a 150 kilowatt station, but say a 1500 watt station, you'd need just under 25 dB range, or 4-bits.
<p>
Now before you start pointing out that there are other issues, yes, there are, sample rate, clock stability to name two. We'll get to those. I should also point out that normally you'd represent the voltage range using both positive and negative values and I didn't mention that the maximum is calculated using RMS.
<p>
In the meantime, I'm getting excited to see my new toy arrive. I'll let you know how it goes.
<p>
I'm Onno VK6FLAB
Listen:
So, you want to be an amateur?
Foundations of Amateur Radio
<p>
The other day I stumbled on a social media post titled "So, you want to be an astronomer..." by /u/Andromeda321 on reddit. Look it up if you're interested how she puts together the prerequisites from her perspective as an astronomer.
<p>
Apart from the fact that a few of my friends are astronomers, one even a radio amateur - and I have to confess, that's a combination that is exciting and intriguing - it got me considering how you become a radio amateur.
<p>
In my mind I started putting together lists and links and other prerequisites that help you become an amateur when it occurred to me that being an amateur is in my view a state of mind.
<p>
While it's true that there is a licensing process that gives you transmission privileges, that to me is not what makes an amateur.
<p>
When I started my amateur radio involvement in 2010 I'd seen amateur radio exactly twice. Once as a sea-scout during a Jamboree on the Air at the end of the 1970's and once when my manager parked his tiny car, I think it was a champagne coloured Daihatsu Charade, with a massive 40m or 80m vertical in the car park at work.
<p>
As I started learning about amateur radio and passed my test I'd commenced the journey into what I now consider to be membership of the amateur community. That same journey is undertaken by people across the planet. For some it starts like mine, with a course. For others it starts with a neighbour or a parent, a friend or an aunt. They might start with listening to short-wave radio, or playing with electronics.
<p>
People start their journey at all different places and times in their life.
<p>
There is a perspective within the amateur radio community that says that you're not a real amateur until you've passed a test.
<p>
I don't think that's right. Passing a test is part of the experience and you may or may not start there, or even pursue the test. That doesn't describe your radio amateur status, that's just giving you responsibilities and regulations that permit you to expand your thirst for knowledge.
<p>
In my experience, the real test of being an amateur lies in something much simpler than that.
<p>
Being a radio amateur isn't a profession, it's a hobby. An amazing one, but a hobby. I know that there are plenty of amateurs that will argue that it's a service. I don't deny that there is a service aspect, but that doesn't take away the rest of the community, it adds to it.
<p>
You might wonder why I'm even bringing this up. The reason is that all too often our community erects fences. "You don't have a license", "You don't know Morse", "You only have an introductory license", "You only own a cheap Chinese hand held", followed by: "You're not a real amateur."
<p>
I think that you're an amateur when you decide to be one.
<p>
So, if you're not yet here, what's stopping you?
<p>
I'm Onno VK6FLAB
Listen:
Permission to be curious
Foundations of Amateur Radio
<p>
The activities that our community places under the banner of amateur radio are many and varied. I've referred to this as a thousand hobbies in one. If you look at the surface, you'll find all manner of activities that readily attach to our hobby.
<p>
Activations for example are invented at any opportunity, from parks to peaks, light houses, bridges, trains, boats, lakes, roads, locators and countries. We pursue contesting, making contacts using different modes, different power levels, we pick the frequencies on which we operate.
<p>
If you dig a little deeper you might consider investigating propagation, or antenna builds, electronics, physics and more.
<p>
It occurs to me that there is an underlying activity, one that any amateur can participate in and most do at what ever level they choose.
<p>
It's the act of being curious.
<p>
You can choose to turn your radio on and be curious to what's going on around you on the bands, or you can be curious as to what the underlying principles are of the mode you're using to make a contact. You can be curious as to the electrical principles and you can be curious as to the maths behind that.
<p>
Superficially you might think that being curious isn't really something that is remarkable. I'm here to disagree with that.
<p>
If you drive a car, you can choose to be curious, but many just put fuel in the right hole and keep air in the tyres. Most will wash their car from time to time. Some will dig into the innards of their car, but the vast majority lacking even a superficial understanding will have their car serviced by an expert. The same is true for computers. You might not wash your computer, but doing maintenance is often a case of waiting for it to die and calling your local IT expert.
<p>
There is absolutely opportunity for curiosity in relation to cars and computers and there are plenty of stories from those who follow that path.
<p>
In our community I think that this balance is completely different. In amateur radio there are a few people who use their radio like the majority of the general public uses their car, but in the whole, I think that the bulk of radio amateurs travel down a rabbit hole on a regular basis, armed with multi-meters, screw drivers and soldering irons. I see their reports, I hear their questions, I read their emails and respond to their requests.
<p>
You might say that I'm biased, since those are the amateurs I come across, but I think that's underselling quite how special this hobby of ours really is.
<p>
I love that you can be curious about an antenna and keep digging and become curious about the underlying laws, right down to the fundamental principles behind the phenomenon we experience as radio.
<p>
I've said many times that getting your license is like receiving the keys to the hobby. You have the ability to open the door and come inside to see and explore for yourself.
<p>
What have you been curious about lately and what did you do about it?
<p>
I'm Onno VK6FLAB
Listen:
First ever digital contact!
Foundations of Amateur Radio
<p>
When you start life you learn early on the difference between being told about an experience and the actual experience. There's a saying that comes to mind, I use it regularly in my day job: In theory there is no difference between theory and practice, while in practice there is.
<p>
I thought I'd do the quote justice to see where it came from, not from Einstein, who was three years old at the time it was coined and neither Yogi Berra or Richard Feynman had been born. Quote Investigator puts it in the Yale Literary Magazine of February 1882 and attributes it to Benjamin Brewster, but I digress.
<p>
A little while ago the regulator in Australia altered the rules of engagement in relation to amateur radio for people holding the license that I do. All Australian amateurs are now permitted to transmit digital modes. Not that this should have been any impediment to the exploration of the receive side, but I had a few other things on my plate to try. Still do.
<p>
Over the weekend I sat in my driveway with my radio and had the urge to see if I could actually do some PSK31, a digital mode that had a low entry barrier, since there were defined frequencies, and I could use a decoder on my phone.
<p>
So, I set about doing just that. I had already programmed in the various frequencies into my radio the week before. I hadn't actually heard any signals, but that didn't deter me. I set about getting myself set-up for what I'm calling a driveway hack.
<p>
Picture this. A folding table with my radio. A stool next to it with me on it. The radio connected to an antenna, a vertical that was attached to a neighbour's roof with a magnetic mount and my phone running DroidPSK. I was tuned to the 10m PSK frequency, had the volume turned up, holding my phone next to the speaker, watching the waterfall.
<p>
Nothing.
<p>
I called up a mate who had this all working and we set about trouble shooting my set up.
<p>
He made some transmissions; nothing.
<p>
I listened to the 10m beacon, loud and clear.
<p>
He made some more transmissions, still nothing.
<p>
Then we realised while I was switching back and forth between the beacon and the PSK frequency that his radio was set up for a different standard PSK frequency. Gotta love standards, there's one for every occasion. Changed my frequency and for the first time I could actually see stuff in the waterfall display on my phone.
<p>
If you've never seen a waterfall display, it's a tool that helps visualise the signal strength of a chunk of spectrum over time. It's pretty nifty and a waterfall displays a lot of information.
<p>
Starting with colour, the idea is that a colour represents a particular signal strength. Red for full signal, yellow for half, blue for the lowest detected signal and black for no signal. Fill in the gaps with the colours of the rainbow.
<p>
If you represent a line made of dots with the start of the line at say 0 Hz and the end of the line at say 3 kHz, you could split the line into 300 dots, and each dot could be coloured to represent the average signal strength for a little 10 Hz slice of spectrum.
<p>
If you wait a second, move the line you drew down and then measure again, you'd end up with two lines. The line from now at the top, the line from a second ago below it. If you do this every second, you'll end up with lines flowing off the bottom of the screen, the oldest lines at the bottom and the newest ones at the top.
<p>
That is a waterfall display. Over time you'll start to recognise what a particular signal looks like on the waterfall and there are even modes where you can draw on the waterfall, but I'll leave that for another day.
<p>
As I said, I could now finally see signals on my waterfall display.
<p>
I'm not going to dig too deep here, because there's much confusion in the language surrounding all this and I intend to get the names straight in my mind before I express them here, but after figuring out that you have to tell DroidPSK which signal you want to decode, I finally managed to decode the transmission from my friend.
<p>
After putting on some headphones and realising that the clicks I was hearing from my phone were actually artefacts from the speaker, I also managed to transmit a CQ signal which my friend decoded. He then acknowledged my callsign in his next transmission.
<p>
So, I now have two screen shots, his and mine, showing that we both saw each other using 10m PSK31. There wasn't a signal strength exchange, mainly because I have yet to figure out how to determine that and where it's visible, but for all the things that matter, I managed a contact with PSK31 thanks to Randall VK6WR, very exciting!
<p>
Since then I've started experimenting with decoding WebSDR, that's HF signals coming in via the internet and being decoded on my computer from the web audio. I'm still working on that, but there is so much to learn and play with and a transmitter isn't yet needed to have fun. I should mention that you can also decode satellite signals like this.
<p>
Digital modes, just when you thought that the rabbit hole couldn't get any deeper.
<p>
I'm Onno VK6FLAB
Listen:
When was the last time you played?
Foundations of Amateur Radio
<p>
The other day it occurred to me that my callsign had been away from HF for months, probably longer. I didn't really want to think about how long it had been. I moved QTH over two years ago and ever since I've been working on a new antenna set-up. You know the kind, you shouldn't rush this. Anyway, having just had a camp-out with some friends for a portable contest, where I gleefully had fun with the station callsign, I thought it was time to actually do what I keep advocating to anyone who stands still long enough, to get on air and make some noise.
<p>
So I did.
<p>
You know that feeling when the longer you wait, the harder it gets and the more you put it off? That had invaded my thinking and my avoidance. The typical excuses of not enough space, too much noise, no antenna, radio not ready, too hard, all fought their way into prominence. I'd had enough.
<p>
So, on Saturday I collected all the bits that make up my portable station. It had clearly been a while since I'd used it, since I couldn't for the life of me remember where the head of my Yaesu FT-857d was, that was until I remembered that it had previously been installed in my car, so that's precisely where I found it. The tiny jumper cable between the head and the body was located in my headset bag where I'd stashed it after forgetting it for a contest one year. The microphone was where I'd stored it in the car. The battery was easier, since I'd used that the weekend before. Pulled out a table, a chair and set about putting my station together right there in the driveway.
<p>
I'd been meaning to test an antenna that to all intents and purposes was doomed to fail, a long-wire on the ground. I didn't have an un-un or a balun, but I did have my trusty antenna coupler, so I used that. One end of the antenna, twelve and a half meters going one way, the other half going at a right angle. That pretty much solved that.
<p>
Then for the final touch, I turned the radio on. All worked and I set about figuring out what I could hear. Across all the NCDXF beacons and bands I could hear the local beacon about 30km away.
<p>
I have mentioned the NCDXF before, but in short, the Northern California DX Foundation has since 1979 coordinated the installation and maintenance of a collection of transmitters that 24 hours a day, every three minutes transmits on a staggered schedule across 5 different bands. It's called the International Beacon Project. For funding, the NCDXF relies on donations from people like you and in Western Australia the WA Repeater Group maintain the beacon, VK6RBP.
<p>
Each transmission consists of a callsign, a beep at a 100 watts, a beep at 10 watts, 1 watt and 100 milliwatts. You can hear the beacons on 20m, 17m, 15m, 12m and 10m. Their purpose is to determine what propagation is like across the world on each of the bands, in pretty much real time. It was the impetus for me to start learning Morse Code - in case you're wondering, no, I know, I'm still at it.
<p>
On my wire on the ground antenna the local beacon on the 10m band was by far the strongest. I also had a listen on 80m and 40m and even found two stations in deep discussion about something or other. Didn't manage to catch their callsigns, but good readability, not so much in the way of signal strength.
<p>
I called up a friend on 900 MHz, in case you're sceptical, yes I hold a licence for that, so do you, it's cunningly encapsulated in a sophisticated portable battery powered multifunctional gadget made of electronics and glass. He was in the middle of repairing some damage sustained to his G5RV Jr. antenna during our latest adventures - Hi Glynn - and afterwards we had a go to see if we could in fact hear each other. I was using 5 Watts, he something like 70 Watts. Neither of us could hear the other, even though we're a similar distance from each other as the beacon. Not yet sure if it was his radio acting up, or mine for that matter.
<p>
I then started down the digital modes path. Installed a PSK31 decoder and set about programming my radio for the traditional PSK31 frequencies. Didn't hear anything, didn't decode anything, but had a ball none the less.
<p>
You might think to yourself right about now what the point of all this was if I didn't make any contacts? The answer is simple, I got outside, in the sun, soaked up some Vitamin D and played radio, just like the weekend was intended for. My next adventures are likely going to involve the same antenna and a vertical for transmit to see how that goes.
<p>
You don't need an excuse to get out and play and when you do you might not make any contacts, but that's not really the point of playing, is it?
<p>
I'm Onno VK6FLAB
Listen:
Breaking the isolation one QSO at a time.
Foundations of Amateur Radio
<p>
In our hobby we regularly talk about its purpose, its need, its usefulness and other potentially abstract notions. Often there's a nod towards science, learning, self-discovery, challenge, emergency service or some other higher order concept. I know I've discussed many of those over the years and encouraged you to find what the hobby means to you.
<p>
There is one aspect of our hobby that's pretty much left unsaid. It's left unsaid because it's obvious, since radio is about communication at its heart, the idea that we use our radios for communication is ingrained and unheralded. You might find a few new amateurs talking about how they made their first contact on the local repeater, or how they want to use the hobby to stay in touch when they're out and about.
<p>
It occurred to me the other day that much of the world is subject to travel restrictions and social or physical distancing requirements. There's places that are in total lock-down and whilst there are strong recommendations for people over 70 to stay completely isolated, that's not yet a requirement where I live. It might come to that, but at the moment the COVID-19 pandemic is changing habits and communities on an hourly basis.
<p>
Technology is often sought as a solution. There's plenty of video-conferences being held. Local amateur clubs are going online to stay in touch with members while face-to-face meetings are off the menu. Then there's the ongoing access to social media, blogs, discussion groups, mailing lists and the like.
<p>
There are a few brave radio clubs using something a little less technical. The radio. Shock, horror, imagine that, an amateur radio club using an actual, you know radio, to talk to each other. I must admit that communication via radio, as obvious as that sounds isn't always the first thing that comes to mind. I've lost count of the number of times when at the local club one member stood outside yelling back into the shack which way the rotator on the Yagi was pointing whilst adjustments were being made - turns out that the rotator was spinning on the mast in the wind. Took a concerted effort, seriously, to actually turn on a hand-held radio and talk to each other, like civilised people.
<p>
On the weekend during F-troop, a weekly net for new and returning amateurs, I also asked how people were doing given the social isolation that is pervasive.
<p>
I also started toying with the idea of running an F-troop every day, then I scaled it back to every Wednesday and Saturday and then it occurred to me that the power to host a net is in the thumb of any amateur clicking their push to talk button and I finally settled on continuing the normal activity of hosting F-troop on Saturday morning at 00:00 UTC for an hour.
<p>
I understand that in a technically connected world with cheap internet and fully functional gadgets like smart phones, the idea of going back to radio might seem like a step backwards, but I'd like to point out that we're radio amateurs. That's like being a chef and ordering take-out when you have a fully stocked kitchen.
<p>
If you're experienced in this hobby you'll know that nobody needs to grant you permission to host a net, but if you're new here you might not. So, to you I say: "You don't need permission to host a net, so get to it."
<p>
There are some things I've learnt since starting F-troop nearly a decade ago. Start small. Depending on the skill-level of the participants, choose an option for hosting it. F-troop is run with a single net-controller, often that's me, and the role of net-control directs who's next to talk. If you're just playing around, the tried and true version is a round-robin net. You'll need to pay attention a little better because you'll need to know who comes after you so you can hand the call to them. There are also variations on this, but again, start small.
<p>
I track contacts in a spreadsheet, but a piece of paper is just fine. Writing down all the stations you hear is a great idea, since it helps you keep track of who's said what. You can add information as it comes to hand. If the net is on HF you might record the signal strength you see when you're listening to each station, as well as the name and location or QTH.
<p>
Pro-Tip, use a new piece of paper for each net and put a date on it. Future you will love you for it.
<p>
My point is that there should be absolutely no impediment to getting on air, making noise and breaking isolation from the comfort of your own shack.
<p>
I'm Onno VK6FLAB
Listen:
Listening from the ground up
Foundations of Amateur Radio
<p>
When I started learning about antennas I was told height is might. The higher the better. For many years I've followed that advice and like a good little parrot I've dispensed that advice. Turns out that as is usual in our hobby, that's not the whole story.
<p>
I first came across a ground based antenna with a BOG, that's a Beverage On Ground antenna. It's essentially a long length of coax that's pointed at what you want to hear. You can either terminate the end, or not, different effects result with plenty of discussion about directivity, angles, lobes and the like.
<p>
One of the things you'll notice with you use a Beverage antenna is that it's quiet. All signals are reduced in strength, but that also means that noise is reduced. Turns out that this pays off and you hear stuff that you've not heard before. Excellent for a field day or if you want to hear some serious DX stations.
<p>
There's plenty of stuff that's not nice about a Beverage antenna. For one, it's highly directional, it takes up lots of space and if you want to listen in another direction, you'll either build a second or third and switch between them. That, or you'll be rolling up and laying out the coax to point at a new DX entity.
<p>
You also cannot transmit with a Beverage antenna. While we're on the subject, often a beverage can be combined with a vertical, one for receive, the other for transmit. It's one of the projects that lying in my to-do pile. I've even got a remote controlled coax switch, but I'm still figuring out how to make my FT-857d do the switching.
<p>
I could stop there, but I came across another idea a couple of weeks ago. At the time I was being introduced to the local emergency communications team. They showed me their HF stand-by gear. Long piece of wire that you could chuck out on the ground and make contact. As a good little amateur I remember thinking to myself, these poor people they have a lot to learn. I'm glad I'm an eager apprentice in learning the art of keeping my big mouth shut.
<p>
During F-troop, a weekly net for new and returning amateurs, you'll find details on vk6flab.com, another amateur was talking about putting a wire near the ground, like about a foot off the turf with great results.
<p>
I tried it on the weekend with a friend. We were out camping for a local amateur contest, miles from anywhere and anyone and I recalled the emergency communications people and the story during F-troop. We had some time to play, so we started with a long-wire, actually, pretty-much a wire dipole on the ground. Plugged it in, turned on the radio, magic. Same kind of sound effect as a Beverage antenna. Nice and quiet, good signals to be heard. We turned the whole contraption 90 degrees, no difference. Since then I've learned that it's pretty much omni directional and unlike a Beverage antenna, you can use it to transmit.
<p>
Of course it's not going to act in quite the same way as a dipole high in the air, and that's pretty obvious, since it's not in the air. It'll give you communications that are called NVIS, or Near Vertical Incident Skywave, essentially stuff that goes straight up and comes down, stations up to about 400 km or so away. For scale, that's enough to cover all of Holland. In Australia it's enough to cover the state of Victoria, or the width of the UK, and most of the width of the State of New York.
<p>
Before you get all huffy and point out that this is not a great DX antenna I'll beat you to it and tell you that this is not a great DX antenna. It's not meant to be. Nor is it intended to be an instruction on what antenna to build next. This is purely intended to illustrate that antennas come in all manner of shapes and sizes and there is lots to be learnt from trial and error.
<p>
I know that this is a "compromise" antenna. Guess what, so is every other antenna. Today the compromise is that we don't need any poles, trees or unsuspecting human support structures to keep an antenna in the air. You can essentially try this one for free at any time, on your own, on the beach, in a park or on the side of a mountain.
<p>
Another great use is to talk to your friends who live in the same city on HF. I have no doubt you could even manage some FT8 contacts using this antenna.
<p>
Next time someone tells you to put your antenna in the air, ask them who they want to talk to. If it's locals, then there is absolutely no need at all. As for mastering the art of keeping my big mouth shut, we'll see.
<p>
I'll leave you with this. It's not the answer that's important, it's the question, for everything else there's experimentation.
<p>
I'm Onno VK6FLAB
Listen:
What level of preparedness are you at?
Foundations of Amateur Radio
<p>
An often repeated statement about the purpose of our hobby is related to emergency preparedness. The various peak bodies around the world devote plenty of resources to the concept, with helpful examples, umbrella organisations, training, coordinators, grants and funding, photo-opportunities and all the other trimmings that come from the idea that you and I are going to be of assistance in the case of some or other emergency.
<p>
Looking up the various emergency coordination groups is a disappointing experience. From broken web-sites with non-existent pages to latest news that's over two years old, through to the latest sausage sizzle and fun-run. Entreaties to make sure that you have your current Membership ID card, otherwise you won't be covered for insurance purposes. As I said, all the trimmings with lots of evidence of paper pushing and little or no evidence of actual preparedness, let alone public information that might help any new or old radio amateur become prepared.
<p>
Back to the topic at hand and leaving aside the nature of the emergency for a moment, given that the response for a bush-fire, a cyclone, flood or pestilence is likely to be different.
<p>
Let's look at the things we have direct control over.
<p>
If you have at any time taken your radio out of the shack and carried it into a paddock, connected it to an antenna, fired it up and made a contact, you're well ahead of the curve.
<p>
There are plenty of amateurs who have never ever considered what going field-portable might look like, let alone tried it. That's fine if you live in a bunker, have independent power and are able to withstand all manner of disaster scenarios, but realistically it likely means that your emergency assistance will be of the kind that's outside the emergency zone. Helpful to be sure, but there's plenty of those stations to be found - unless the issue is global, in which case we have a completely different set of problems, pandemic, anyone, anyone?
<p>
Let's focus on the other side of the fence.
<p>
You're in an emergency zone. Doesn't matter what kind of emergency. Communications are limited or overwhelmed, information is restricted, messaging is hampered and you're a radio amateur with a working radio. If all goes well you should be able to help.
<p>
So what does a working radio look like and what does helping mean?
<p>
First thing to think of is power. Have you got a battery? Is it charged? When was the last time you tested it? How long has it been sitting on the shelf? Did it discharge in the meantime? What about a charger? Have you got a generator? What about fuel and oil? What about spare parts? Have you got something else, like a solar panel, a wind generator or a water turbine? What about a push-bike with a dynamo attached? How long does your radio run on a battery and at which transmitter power level is that?
<p>
After thoroughly investigating power, what does your actual emergency station look like? Will it be used for voice communication, or will it be used as a digital gateway? Can you use it to send rudimentary messages, or can it be used as an internet gateway for a local community?
<p>
What bands are you planning to operate on? Do you have an antenna? What happens if your current antenna is taken out by a fire, lighting strike or something else? When was it last tested? Do you have a back-up antenna? Have you actually used this antenna? Does it have all the right connectors and are they with the antenna?
<p>
So, pretend that you got all that right. What about you? Have you got spare clothes? Food? Shelter? Medication? What about Personal Protective Equipment, masks, gloves, what-ever? What about ancillary items like pen and paper? Do you have power for the laptop that's being used to create the digital mode messages?
<p>
Note that I've not said a word about the usefulness of any of this. This is the base level of preparedness just so you can actually look yourself in the mirror and say that you have at least got a level of ability to be of assistance in the case of an emergency.
<p>
You can of course argue that you should hook up with the local emergency services and offer your skills as a radio amateur. That's helpful, but what if you cannot actually go to the muster point? How does that help?
<p>
Now lets pretend that you actually have done all this. When was the last time you tested it?
<p>
What does the actual helping look like?
<p>
Have you ever attempted to pass emergency messages? What about messages that must be transferred absolutely 100% correctly, think medication dosages? Who did you pass them to? When was the last time you did a regional emergency simulation between your amateur friends? How often do you do this? Once a decade, or more often than that? What if the local repeater isn't working? What about in your club or your local neighbourhood? Do your neighbours even know you exist?
<p>
The point of all of this is to reveal that the level of emergency preparedness for radio amateurs is in my opinion spotty at best. If you disagree with me because you are prepared I'd like to ask if you helped prepare your local amateur community and the wider community around it? I don't doubt that there are individuals, even groups who are prepared, but I suspect that they are far and few between.
<p>
When was the last time you actually went into the field for a week and played radio, for real, battery only, limited resources, no outside help?
<p>
I'd love to believe that this is universal, but you and I both know that there is plenty more to be done. How realistic is your emergency preparedness and what are you going to do about it?
<p>
I'm Onno VK6FLAB
Listen:
On the shoulders of giants we stand.
Foundations of Amateur Radio
<p>
One of the things I love most about this hobby is the ability to randomly dart off into any related direction and learn new stuff. For example, the names Nikola, Guglielmo, Heinrich and Edwin emblazoned on a t-shirt sent to me by a very appreciative listener Jack KI4KEP, started an exploration into the deeds and misdeeds of the people behind those names.
<p>
The first three might be somewhat familiar, Nikola Tesla whom we have to thank for inventions like Alternating Current, the Tesla coil, wireless power, radio remote control and many others. The Tesla company is named as a tribute to him. The magnetic flux density uses the letter T as its symbol and its called the Tesla.
<p>
As a side note, if you've ever struggled to decide if a symbol needs to be a capital letter or not, like say the V for volt, the A for ampere, the O for ohm, the m for meter, the s in second or the K in kelvin, you just need to remember that if the unit is named after a person, the symbol needs to be a capital letter. That does assume that you know that the unit is named after an actual person, like say the Earl of Sandwich.
<p>
Name two in our list, Guglielmo Marconi is the person whom we can thank for the practical development of radio communication, using improved spark-gap transmitters, the development and commercialisation of long-distance radio transmissions and his association with many other services such as a transatlantic radio-telegraph service, providing communications to shipping such as Jack Phillips and Harold Bride who were employed by the Marconi International Marine Communication Company to act as radio operators on the RMS Titanic on its fateful voyage.
<p>
Our third name, Heinrich comes into sharp focus when I add his surname, Hertz. His name continues on in our day-to-day language and Heinrich Hertz is responsible for validating many of the underlying principles of our hobby. Using a spark-gap transmitter he was the first to conclusively prove the existence of electromagnetic waves which were predicted by James Clerk Maxwell. He also came up with the parabolic antenna, the dipole antenna, measurement of electric field intensity, electromagnetic waves and many other experiments. If you've ever seen a bullet hole in glass, you've seen a Hertzian cone.
<p>
The last name had me stumped. It took a question to learn that Edwin shares a name with a famous cyclist and a famous astronaut, namely Armstrong. Edwin Howard Armstrong has been called "the most prolific and influential inventor in radio history".
<p>
If you're like me you may not have heard of Edwin Armstrong. You might be surprised to learn that he's responsible for the regenerative circuit, the super-heterodyne circuit and while he was working on defending his invention against a claim made by a patent attorney he stumbled on the super-regeneration circuit. If you're a radio amateur, you'll likely have heard those terms, if not, they're electronic circuits that make radio receivers more sensitive which forms the basis of many radios in use today. My Yaesu FT-857d is a super-heterodyne radio for example.
<p>
It doesn't stop there. The biggest claim to fame that Edwin Armstrong brings to the table is the invention of FM radio. It took many years and a protracted lawsuit that lasted until almost a year after he died to finally have Armstrong formally established as the inventor of FM.
<p>
Not for a minute will I suggest that my exploration was comprehensive or in-depth, but it made my day when I put on a t-shirt with the names of those inventors who made it possible for me to be here and share this with you today.
<p>
On the shoulders of giants wearing a t-shirt with their names I stand.
<p>
I'm Onno VK6FLAB
Listen:
All bands + All modes + All countries
Foundations of Amateur Radio
<p>
A regular lament is the lack of things to do in our hobby. I know, it's foreign to me, but there are plenty of amateurs who express frustration at the lack of activity, no contacts, nothing new, no challenges.
<p>
For my poison, I started the process of contacting 100 different countries using 5 Watts. I've been at it for a number of years and truth be told, since my latest domestic move, over two years ago now, my efforts have been put on hold. Not because I didn't want to, but because I was getting annoyed with having to leave my home and wanting desperately to have a functional shack at home. As you might know, that's a project that's still in hand and thanks to some magnificent assistance from various places, I'm still making progress.
<p>
That said, your perspective might be dulled by the notion that this pretty much concludes the on-air activity possibilities that exist. Within my own license class, until recently, I was permitted to use voice modes like SSB, AM and FM and I was permitted to use hand-keyed Morse. I have access to 10 Watts and am currently allowed to use six different amateur bands, namely 80m, 40m, 15m, 10m, 2m and 70cm. So together with the four modes, I'd be able to make 24 different contacts to 100 different countries, that's 2400 different combinations.
<p>
Of course there are more than 100 countries, that is, DXCC entities. The 2018 list has 340 of them, so that's over 8-thousand different options for getting on air and making noise.
<p>
Last year all that changed. The local regulator in Australia, the ACMA decreed that all amateurs in Australia were permitted to use all modes.
<p>
It's taken a little while for that to sink in. Specifically what it means for me.
<p>
A quick search reveals that there are at least 60 different digital modes, think RTTY, Olivia, PSK31, etc. In addition to those, there's a plethora of other modes like IRLP, AllStar Link, EchoLink, CODEC2 and Brandmeister.
<p>
So conservatively I'm going to estimate that I now have got access to over a hundred different modes, across six bands with 340 countries, that's over 200-thousand different options for making a contact.
<p>
Of course it's unlikely that I'll make a contact between say Belize V3A and Perth VK6 on 2m using Olivia, but even if we limit our calculation to HF, we still have at least 136-thousand opportunities for adding something interesting to your logbook.
<p>
I've been hunting for a canonical list of all the various amateur modes and the tools needed to make and receive them. No doubt that will take me some time. I'll be documenting it on the projects page on vk6flab.com if you want to follow along. Speaking of which, you'll also find past episodes of this podcast there.
<p>
I suppose I should start by converting my current efforts into some pretty pictures that show what I've been up to so far, but that's a mapping exercise that I'll have to add to my to-do list, since I'm guessing it involves learning how to use some fun mapping tools.
<p>
If 136-thousand opportunities isn't enough, you can also add grid-squares, large and small, different prefectures in Japan, provinces in the Netherlands, CQ zones across the world or ITU areas, prefixes and operating modes.
<p>
Clearly there's plenty to do and see.
<p>
I wonder if there's an award for all modes all bands all countries and I wonder what happens if someone invents a new mode?
<p>
I'm Onno VK6FLAB
Listen:
The impersonal nature of digital and other myths
Foundations of Amateur Radio
<p>
The other day I bumped into a concept that I've heard repeated before. The so-called "impersonal nature" of digital modes.
<p>
There's this idea that any communication that isn't using voice, is devoid of the human touch. Often this assertion is specifically made in relation to modern digital modes like JT65 and FT8. As an aside, I've never heard it in relation to other digital amateur modes like slow-scan television, RTTY or PSK31.
<p>
In the early 1900's when amateur radio was beginning to be a thing, the means of communication was Morse Code. With beeps across the globe contacts were made between amateur stations. With every incoming dit and dah, letters were received, words constructed and meaning derived. This is long distance communication in its early stages.
<p>
Each amateur was said to have a fist, their particular rhythm of touching the key. Across multiple stations it was possible for an experienced operator to distinguish between two amateurs based on how they were sending Morse Code. I can confirm that if you've ever had the privilege of hearing lots of amateurs clamour in a so-called pile-up, you can hear for yourself that different stations sound different, even if they're all sending Morse Code.
<p>
So on the one hand we have this deeply inhuman means of communications like Morse Code which is by the language we use considered to be made by humans, personalised with a fist. On the other hand we have a deeply technical mode like FT8 which isn't.
<p>
During the week I was discussing this change of perception during a haircut. I pointed out that this happens everywhere. For example, in the hairdressing profession an electric clipper might have been seen as impersonal when it was invented in 1921. Today it makes quick work of a Number 1 cut. In mobile phone communication an SMS was seen as impersonal with voice preferred, but today the world would look quite different without the 5 billion messaging mobile phone subscribers. In 2013 it was estimated that there were 8 trillion SMS messages, and 10 trillion other smart phone messages. As you might realise, behind each of those messages is a human, well, apart from the SPAM and the computer notifications, but even those are programmed by a human.
<p>
So what makes the difference between Morse Code and FT8? Why is an SMS impersonal in 1992, but preferred by most today?
<p>
I'd hazard a guess and state that the experience of the person making the statement has a lot to say about their perception of the nature of the medium.
<p>
My typing away at a keyboard and seeing words appear on my screen might not appeal to someone who chased a turkey around the yard in search of a quill, but then electricity might also be surprising.
<p>
It's interesting to me that PSK31, something that's not particularly thought of as being impersonal, was introduced to the amateur radio community in December 1998 by Peter G3PLX. The first Weak Signal modes, commonly known as WSJT modes, were introduced in 2001 by Joe K1JT, only three years later. JT65 came around in 2003. We have this situation where PSK31 is not impersonal, but JT65, which is five years younger, is considered impersonal and the popular mode FT8, which is an extension of JT65 is said to be the end of the hobby.
<p>
If hyperbole would relate to truth, the end of our hobby in sight, we should all get rid of our radios and hand back our licenses.
<p>
Perhaps we should take a step back and notice that behind every FT8 station, behind every voice-call, behind every amateur transmitter is at some point a human with a license. If we're splitting hairs, then a local automatic voice repeater must be the height of impersonal.
<p>
The other thing I'd like to point out is that how you perceive the use of a particular mode is also important. If you think of FT8 as having a personal beacon in your shack that uses your radio and your antenna to measure how well your signal is heard across the globe, you might just start enjoying this so-called impersonal mode.
<p>
One of my friends, Wally VK6YS, now silent key, told a story where he was driving down the highway to meet his friend. They were chatting away using Morse Code, Wally in his car, the friend in his shack. Once Wally arrived the friend wanted to see how Wally was able to send Morse Code whilst driving and could he please see his Morse key? Wally confessed to having whistled into his microphone to make the contact, since he didn't have a Morse key in his car. According to Wally, his friend was off the air for months in disgust.
<p>
I should mention that my Number 1 haircut looks great, if only for the fact that it allowed me to spend some quality time discussing and contemplating the nature of the hobby that I love.
<p>
I'm Onno VK6FLAB
Listen:
The chicken and the egg, which comes first, the antenna or the radio?
Foundations of Amateur Radio
<p>
In my day to day activities as a radio amateur I come in contact with people across all parts of their amateur journey. Some who don't yet know that they're amateurs, through to those who've just passed their test and are waiting for their callsign. Then there are those who have been amateurs for a while, experimented a bit and have settled down into the comfort of being a member of an active community. Stretch that further and I also spend regular quality time with amateurs who have been licensed longer than I've been alive.
<p>
Recently I received an email from a freshly minted amateur. Just like me, still pretty much wet behind the ears, keen as mustard, trying very hard to figure out what to do next and where to go.
<p>
The basic gist of the email from this amateur was that they didn't know what kind of antenna they could erect at their home and failing that, couldn't decide on what radio to acquire to match the antenna that they hadn't decided on, not to mention that the antenna needed to match the radio that didn't yet exist.
<p>
If you've been around this community for a while you might recognise the chicken and the egg, which comes first, the antenna or the radio?
<p>
The answer is obvious, hidden in plain sight, easy to deduce, simple to understand, and completely useless.
<p>
Let me help you with the answer: It depends.
<p>
If that didn't test your patience, even if you've been an amateur for longer than my parents have been alive, you'll know that this is an unanswerable question.
<p>
So how do you break the egg and get started?
<p>
Easy.
<p>
Start somewhere.
<p>
As it happens I have a recommendation. It's cheap, simple and it will get your feet wet sooner rather than later. My recommendation is neither, or both, depending on your perspective. I promise, I'll get to the point shortly. The reason I'm making it last and savouring the point, some might say, belabouring it, is because it's one that happens over and over again, day in, day out, year in, year out.
<p>
My recommendation is that you spend $25 on an RTL-SDR dongle and hunt around your home for a piece of wire. That's it.
<p>
If you're not familiar with an RTL-SDR dongle, it's essentially a USB thumb-drive sized device that plugs into the nearest computer and paired with the correct software it has access to many if not all of the frequencies that you as an amateur are allowed to play with.
<p>
Given that it's a receiver, the antenna doesn't really matter all that much, at least not initially, so any piece of conductive wire will suit. Most dongles even come with an antenna of sorts, so you can get started straight away.
<p>
Resources associated with this podcast are on the vk6flab.com website where I've also collected a few links under F-troop to get you on your way with an RTL-SDR dongle.
<p>
The purist radio amateurs will likely arc up at this point and mention that this isn't real amateur radio, to which I can only say: Bah Humbug. Radio is about receiving as much as it is about transmitting. Any fool with two bits of wire can transmit, but it takes finesse to receive, so start there.
<p>
There are other benefits from going this way. Other than ease of entry, that's another way of saying - cheap - you can easily spot where and when there is activity. You can use all the traditional modes like CW, SSB, AM and FM, but you can also play with all of the new modes like WSPR, FT8, JT65 and investigate some of the other modes like RTTY, PSK31, Olivia, SSTV and others.
<p>
All this will help you have a better idea of the landscape you're stepping into without a major purchase.
<p>
To really set a cat among the pigeons, I'm also looking into a Raspberry Pi based transmitter, rpitx by Evariste F5OEO. When that bears fruit I'll let you know. In the mean time, play, learn, listen, experiment. No need to spend hundreds or thousands of dollars while you're still unsure.
<p>
Even if you already have a lovely amateur station, an RTL-SDR dongle is worth every cent and then some.
<p>
I'm Onno VK6FLAB
Listen:
Exploring an understanding of filters and circuits.
Foundations of Amateur Radio
<p>
Every person is the product of their environment. Unsurprisingly this is even true for radio amateurs. That's not too say that we can't break our mould, but it takes effort. I grew up around technology in the 1980's. As a result I'm familiar with 8-bit microprocessors like the Motorola 6502 which featured heavily at the time. I tend to think in terms of the presence or absence of a signal, rather than the intricacies of circuits and components.
<p>
As a child of my time, I'm not particularly familiar with the punch card or paper tape, or core memory, or valves, 386 machine code or what's in an FPGA. As a direct result of my age, my knowledge and understanding of circuits is sparse at best. I understand basic components like resisters and capacitors in a DC setting, Ohms Law and the fun you can have with a battery, a few resistors, diodes and an LED light.
<p>
As a radio amateur I've been introduced to how some things work differently in an AC circuit, like an antenna and a feed-line.
<p>
Until very recently my knowledge about filters was based on what I'd read. I know that there is fun to be had with coax and stubs and other cute things, but how and why they work eluded me. Today I'm a step closer.
<p>
Before I dig in and share some of what I've learnt, let's have a quick look at what a filter is and does. You'll have likely heard of high-pass and low-pass filters. You might have heard of band-pass and band-stop filters.
<p>
If you think of a high-pass filter as a device that lets through high frequencies and a low-pass filter as a device that lets through low frequencies, we're already well on our way. If you put a high-pass filter together with a low-pass filter, you end up with a range of frequencies that doesn't pass, known as a band-stop filter.
<p>
Similarly, if you tweak the frequencies that pass just so, you can combine a high-pass and a low-pass filter to make a band-pass filter.
<p>
Let me illustrate.
<p>
Imagine a 15m band-pass filter. It allows all frequencies in the 15m amateur band through, but blocks everything else. You could construct such a thing from a high-pass filter that allows 15m and above through combined with a low-pass filter that allows 15m and below through. Everything below 15m is stopped by the high-pass filter and everything above 15m is stopped by the low-pass filter. The gap between the overlap of the high-pass and low-pass filters is what creates a space where the 15m band gets through.
<p>
If you move things around a little, the same can be constructed to make a 15m band-stop filter. Something that lets anything through, except a 15m amateur signal. To make such a gadget would require a low-pass filter that allows everything below 15m combined with a high-pass filter that lets everything above 15m through.
<p>
So, if you can construct a high-pass filter and a low-pass filter, you can pretty much create any combination and allow or stop specific frequency ranges.
<p>
If you're wondering why this might be useful, think about a contest. Two radios in the same shack. One transmitting on 15m and one on 40m. These two bands, one at 21 MHz and one at 7 MHz are third harmonics to each other. This means essentially that a radio on 40m affects one on 15m and vice-versa. If you had a set of filters that stopped 15m and passed 40m on one transceiver and a set of filters that stopped 40m and passed 15m on the other, both of you would be much happier.
<p>
You don't need to do contesting to benefit from a filter. If you use an RTL-SDR dongle, it's affected by nearby strong signals, like say a local radio or television station. That's fine if that's what you're trying to hear, but not so much if you're trying to hear something else. Filters can help to make your life better.
<p>
Now, to round this off at a suitable point, you can think of an inductor as device that lets low frequencies through but blocks high frequencies. Similarly, a capacitor is a device that blocks low frequencies but lets high frequencies through. So, it's fair to think of an inductor as a low-pass filter and a capacitor as a high-pass filter. The symbol for a capacitor is the letter C (Charlie) and for an inductor it's the letter L (Lima).
<p>
You could make a circuit that either directly blocks from a certain frequency, or one that lets it through, but sends it to ground. This gives you two designs for a low pass filter one using an inductor or an RL circuit and one using a capacitor or an RC circuit. Similarly you can create a high-pass filter using either an inductor or a capacitor. That gives you four designs for two filters.
<p>
Each of these can be combined to create band-pass and band-stop filters.
<p>
The maths behind it isn't particularly daunting with basic high-school maths and if you want to see it happen before your eyes, check out the "Organic Chemistry Tutor" on YouTube. The play list you're looking for is cleverly disguised as "Electronic Circuits".
<p>
As a direct result, I started hunting for breadboards, but it turns out that you can simulate these circuits online using any number of simulators. Of course there's going to be a gap between simulation and reality, but that's when you get out your soldering iron.
<p>
Remember, if you smell chicken, you're holding it wrong.
<p>
I'm Onno VK6FLAB
Listen:
How I care for my connectors
Foundations of Amateur Radio
<p>
If you've ever found yourself in the position of attempting to screw a PL259 into an SO239, or an N-type plug into an N-type socket you'll have likely come across the situation where the thread doesn't quite fit. If it does, you might have issues attempting to undo the connection, even if you didn't particularly do anything strenuous in relation to mating the two in the first place.
<p>
This kind of situation happens to me more than I think is reasonable. It happens on cheap connectors, on expensive ones, on the back of radio gear, on adaptors, patch leads and the like.
<p>
Initially I put this down to cheap vs. expensive, but that really doesn't add up if you're attempting to connect an expensive plug into an expensive radio.
<p>
If you're into machining you'll know about swarf. If not, think metallic dust. Of course it doesn't have to be metallic, it could be a single grain of sand, or it could be a slightly damaged thread.
<p>
A couple of months ago I went on the hunt for a tap and die set that would solve this issue once and for all. If you're not familiar with the terms, a tap is like a long bolt with a square head and a die is like a thick washer with holes cut out.
<p>
In addition to being hardened, they each have cutting edges, which allows these two tools to do their job, the job of cutting threads.
<p>
Normally you'd use a tap to make a thread into a hole that you've drilled. You'd use a die to make a thread onto a rod that you have. There's lots of technique associated with this, cutting fluids, alignment, pressure and the like. Plenty of relaxing YouTube videos around - which is how I came upon this idea in the first place.
<p>
You can also use a tap or a die to cut across an existing thread and you can do this with connectors.
<p>
A die, threaded over a socket, will clean up the socket threads. Similarly a tap screwed into a plug will clean up the plug thread. There's a disclaimer coming for that last point, but stick around.
<p>
Trying to find a tap and die to match can be a challenge. The PL259, SO239 and N-type connectors are all 5/8th size threads. They're 24 turns per inch, and also known as UNEF (Uniform November Echo Foxtrot) threads, or Unified Extra Fine.
<p>
So if you start on your hunt, you'll be looking for 5/8th, 24 TPI, UNEF taps and dies.
<p>
I found mine online at $15 or so from a US supplier. Got to me in about a week.
<p>
When they arrived I immediately set about cleaning up all my sockets. This was amazing, all of a sudden stuff started fitting well. Unfortunately I couldn't use the tap. The centre hole in a standard tap isn't big enough for the pin of a PL259, let alone an N-type connector, but a friend of a friend has access to machine tools and made the centre hole bigger. Word of warning, this is hardened steel. A hand-drill won't cut it.
<p>
I must mention that this won't allow you to use the tap inside an N-type plug, but you can use a die on the socket.
<p>
I'll also point out that if you need to use a tap wrench or a die holder, you're doing it wrong. We're cleaning up the thread, not making a new one. If you need extra force the most likely scenario is that you've cross threaded the tool onto the connector.
<p>
Of course if you've got a completely stuffed connector thread, then these tools can help, but you might want to consider replacing the connector.
<p>
My tap and die live in my go-kit right next to the coax adaptors. On my next field-day I won't be having to deal with poor connections, nor will I have to worry about unscrewing them after the event.
<p>
A tap and die, great simple tools to fix a recurring issue.
<p>
I'm Onno VK6FLAB
Listen:
How I host a weekly amateur radio net for new and returning amateurs
Foundations of Amateur Radio
<p>
If you've ever had the pleasure or misfortune to hear an on-air net, you might have considered, however briefly, how that net came to be, how it's run and what's involved behind the scenes to make it happen.
<p>
I host a weekly net called "F-troop". It's been running every week since the 12th of June in 2011. Since then I've made over 5000 contacts with stations scattered all over the globe. A typical net has about ten people, but depending on the weather, what's on TV or if people had a hard Friday night that number fluctuates. The biggest was about 40, the smallest just two.
<p>
At this point I could tell you that the infrastructure to make this happen, the preparation, management processes, network and marketing are what take up the bulk of my week. I mean, there might be a weekly stand-up between stakeholders on a Wednesday, a plan for the content, what to discuss, you know, the typical.
<p>
If I told you that, I'd be lying.
<p>
The reality is that F-troop is an organic animal. I generally get to my radio a couple of minutes before we start, midnight UTC, switch on, kerplunk the local repeater and wait for the clock to tick over.
<p>
I then launch into my opening spiel, something along the lines of: "Hi folks, it's me, it's F-troop, who's awake?"
<p>
After taking a few calls and logging them, I'll circulate through, call for more people, rinse and repeat.
<p>
There are two invisible things happening, one required, the other I do because I'm a computer geek. The required activity is logging. I chose to log in an online spreadsheet. It's helpful because it makes for a single place where all contacts are stored and it allows for others to host the net if I happen to fall off the air, either by being somewhere else, like a holiday every decade or so, or because my radio isn't being cooperative.
<p>
The other thing that logging gives you is a memory. I generally recall a person's name from their callsign, but if you listen closely you'll notice that every now and again I'll extend my babble so I can search for a callsign and appear not to be suffering from memory loss.
<p>
The other thing that happens is that I update the website. I'll be merrily adding articles from emails or discussion as it's happening. If someone mentions a product or a website, a callsign or a project, I'll often be searching for it in real time and adding it as a post to the F-troop website. That way people who want to refer back at a later time, that includes me, can search and find the thing that someone showed us.
<p>
As simple or as complex as that sounds, depending on your level of experience, it's really not rocket science. You can do this with pen and paper. I know, I've done it, standing in a car-park with a notepad, whilst dodging rain showers and preparing for a field-day. It's fun to test your skill and to get out of your comfort zone every now and again.
<p>
I should interrupt this story for a word from our sponsors. Don't have a kitten, we're not talking about advertising, we're talking about repeater and network operators who graciously give of their time and resources to link the main F-troop repeater to others around the world. The network of AllStar, Echolink, IRLP and IRN radios that carry F-troop is astonishing to me. We have regular participants all over Australia, the United States and the United Kingdom. There have been contacts with stations in Asia and Europe.
<p>
For that to happen I don't do a single thing. Well, technically I let repeater operators know I exist and when it breaks, but that's pretty much the sum total of my efforts.
<p>
Why am I telling you this?
<p>
Last week it broke. My radio was acting up and someone commented on that. I handed over the reigns and let them at it. They were very unsure. I let them know that F-troop is for beginners. It's expected that people are going to make a mistake, I know I do, plenty of times.
<p>
It occurred to me afterwards that hosting a net can be scary. If you have no idea what's involved, how to make it happen, what to do, then hosting must be immensely daunting.
<p>
I hope that sharing how I do this will give you the confidence to host your own net in your own community. Perhaps you can tell me more about it, or come and visit F-troop. Saturday morning at midnight UTC. If you want I'll even help you host it.
<p>
I'm Onno VK6FLAB
Listen:
Is this frequency in use and other lies we tell ourselves.
Foundations of Amateur Radio
<p>
When you switch your radio on to start a radio fishing expedition you join all the other spectrum users across the planet. To be fair, you'll likely only become aware of some of those for the time that your radio is switched on, even if there are thousands around.
<p>
One of the ways you can find other users is by ditting out "QRL?" in Morse or saying "Is this frequency in use?" into your microphone.
<p>
This simple courtesy of checking to see if the frequency you're on is actually being used by someone, is part of your license. You're taught to do this and it's expected.
<p>
What's not clear is what happens next.
<p>
It's simple if you hear a callsign, or a "yes", but what if you hear nothing?
<p>
Sometimes nothing means exactly that, there's nobody on the frequency, but that's not always the case. There's plenty of opportunity for the frequency to be in use and you still not getting a response back.
<p>
Let's imagine for a moment that the frequency you're on is in use by two stations talking to each other. You come on frequency, hear nothing and ask if the frequency is in use. You hear nothing. You try again, still nothing. You start calling CQ. Moments later, you get an earful from some random station.
<p>
Sound familiar? If it doesn't, you'll need to spend more time on-air. I can guarantee that you'll experience this in your amateur adventures, much more than once.
<p>
How does this happen? You did everything right.
<p>
Imagine two stations, let's call them Amanda VK4FRST and Marc VK3OHM, having a conversation, a QSO. They're discussing the ins- and outs of the WIA awards system and having a grand old time.
<p>
You turn your radio on, happen to tune to the same frequency as their QSO and after listening to nothing for a bit, you call "Is this frequency in use?". You still hear nothing so you try again: "Is this frequency in use? VK6FLAB". Still nothing. You call "Nothing heard." and start calling CQ.
<p>
You're on one side of the country, Amanda and Marc are on the other side. They cannot hear you and you cannot hear them. Then the sun moves a bit and all of a sudden your CQ is all over their discussion. Unhappy people on both sides of the country.
<p>
There are six paths to consider here. The one between you and Amanda, and the reverse. Similarly the path between you and Marc and that reverse. If you ask for frequency in-use, neither Amanda, nor Marc can hear you. Similarly, you cannot hear either Amanda or Marc. You should also take a moment to consider the path between Amanda and Marc and vice-versa. They might have a really great 5 and 9 conversation, or they might be struggling along with a 3 and 2.
<p>
I've simplified this, because of course, you calling over the top of a conversation can also disturb the contact under way. Saying that the frequency is in use makes it worse.
<p>
While all this is happening, the sun is moving, the ionosphere is moving, propagation is moving, the whole thing is like the Cat in the Hat balancing on a beach ball, complete with cake, rake and a fish still in its bowl.
<p>
The first thing you need to do when this happens is stop and take a breath. Nobody owns any frequency, so claiming that this is your frequency is not going to help anyone. If the other station is having a QSO and you're calling CQ, it's time for you to move, change frequency and QSY.
<p>
If you're Amanda or Marc, you can tell your contact that there is some interference and then call the other station that the frequency is in use. If they change frequency, all good, if they don't, tell your contact to change frequency.
<p>
There's no need for aggravation. There is no ownership. There's no point in getting upset and no mileage in making life hard for the other station. The fact of the matter is that there was what we call in networking, a collision. It's time to back off and renegotiate.
<p>
All this is exactly the same if you're using voice, Morse, FT8, or any other mode.
<p>
Take a breath, renegotiate, move on.
<p>
Now, if you're a QRP station like me, it's much more likely that you'll not be heard most of the time. In that case it's often much quicker to just to move without going through the negotiation process. Of course you can attempt to make a QRP contact with one of the other stations, but it's considered pretty rude to stick your head between two people who are having a cup of coffee together and ask them for their autograph, so don't do it on air either.
<p>
If you assume malice from the get-go, you'll find yourself unhappy most of the time. If you celebrate that all of a sudden there's propagation between VK6, VK4 and VK2 you'll end up much happier with your on-air experiences.
<p>
While I'm giving out advice, here's something I learnt during the week.
<p>
If you break a toe, tread carefully. Stubbing a broken toe hurts. Really. Badly. In case you're wondering, my new boot is not a fashion accessory.
<p>
I'm Onno VK6FLAB
Listen:
The lessons we teach.
Foundations of Amateur Radio
<p>
When you become a member of the amateur radio community you become part of a small group of humans who know and understand certain aspects of life. That's not to say that others don't share this or that the knowledge is unique or special, but radio amateurs are required to know this before they receive their license.
<p>
In the past I've spoken about how getting a license is like receiving a key that opens the door to the world of radio communications. It's one of the more accessible ways to grab hold of this key and it's the recipe for life long learning.
<p>
During the week a friend of mine, a newly minted amateur, pointed out that this represents something that the general population isn't aware of or attaches little in the way of value to. The interconnectedness of radio spectrum is something that radio amateurs take for granted. To us it's obvious. A transmitter on 3585 kHz is fundamentally the same as one on 92.1 MHz. A key fob on 434 MHz is similar to a computer on 2.45 GHz as is a laser on 500 THz or an X-ray machine on 30 PHz.
<p>
As a radio amateur we're taught that the radio spectrum is a continuous phenomenon and that spectrum is shared among users with specific rules around interference and interaction.
<p>
Another thing we know as radio amateurs is the difference between the front and the back of a Yagi-antenna. We know about radiation patterns, about the ionosphere and how the sun and sun-spots interact with some of our activities.
<p>
The point is that our knowledge, it's fair to say, specialised knowledge, even at the lowest level of licensing, exceeds that of the general public.
<p>
This is all by way of background because this leads to something that I learnt during the week.
<p>
As amateurs we have a responsibility to be custodians of that knowledge, that is, to care for it and to ensure its accuracy and to preserve that knowledge.
<p>
For some amateurs that means that they want this information to be exclusive, but for me it means that this information should be shared and nurtured and encouraged in those people who make choices based on incorrect information.
<p>
For example, as a radio amateur it's my duty to inform a person who is contemplating breaking the radio spectrum licensing rules that they are doing so. Not because I'm a regulator, but because I have specialised information that they lack. Importing a radio module that's using a frequency that's not available in your country is an example of something that I am compelled to point out.
<p>
I know that some amateurs take this compulsion to the next level and become a de-facto police officer attempting to enforce those restrictions. I understand where that comes from, but I also know that this is not my role and it's not your role. If you feel strongly enough about a transgression, perceived or real, there are plenty of ways to deal with that. Reporting the offence to the regulator is one option for example.
<p>
Knowing which end is the front of a TV antenna means that you can point out a mistake to a home-owner about the direction their antenna is pointing at, but it doesn't mean that you need to climb on their roof to turn it around.
<p>
I've said many times before that having an amateur license is a privilege. It's a gift, even if you worked hard for it, it was given to you, bestowed on you by the regulator in your country.
<p>
It seems to me that having such a gift means that it should be treated as such. As radio amateurs we're not entitled to a license, nor are we entitled to transmit. We're granted permission to do so.
<p>
I think that it's important to keep that in the back of our minds when we set out to educate those around us.
<p>
As for the education itself. It pays to consider what you take for granted when you're giving advice. Telling a person about Wi-Fi propagation through a home is a complex topic. You can make the explanation as hard or as simple as you want, but don't expect that the person receiving the advice has the same background information or interest that you have.
<p>
I was once told by a statistician about how various statistics worked and what their background was. I was translating a program from Modula-2 into WingZ hyper-script. I didn't care about how it worked, just that the provided code did what it was supposed to and that what I wrote did the same thing. I had no interest in becoming a professor in statistics, despite the earnest instruction enforced on me by my employer 30 years ago.
<p>
It's been said that you must learn from the mistakes of others. You can't possibly live long enough to make them all yourself.
<p>
What and how we teach those around us can be the seed of something bigger. I may well have become a statistician if the information had been tailored to my requirements, but that chance was lost 30 years ago.
<p>
I think it's a great way to consider what we teach and how.
<p>
I'm Onno VK6FLAB
Listen:
What's in a plan?
Foundations of Amateur Radio
<p>
As radio amateurs we learn which frequencies we're allowed to transmit on, where stuff lives and who has priority when there's a signal on the frequency you're operating on and when you need to contact your regulator if you hear an illegal station on the air.
<p>
Some of that information arrives in your brain by way of the education process that eventually becomes your license after a test. Depending on which country your license is valid, determines which region of the International Amateur Radio Union your activities fall.
<p>
Here in Australia, I'm part of the IARU Region 3, together with the rest of the Asia - Pacific region. In the Americas you're part of Region 2 and Europe, Africa, the Middle East and Northern Asia fall into Region 1. As amateur population sizes go, Region 2 and 3 each cover about 40% of all radio amateurs. Region 1 is about 20%.
<p>
Each of these IARU regions has a specific band-plan that is updated regularly as member countries adapt and negotiate different frequencies for different users. The band-edges might not change that often, but bands come and go, segments are added and removed as needs change. For example, here in Australia or VK, the 6m band has been changing because analogue TV has been changing.
<p>
Information about band-plans is not easy to come by. For example if I look at IARU Region 2, their documentation is pretty sparse. I've never managed to actually load their website and by the looks of it, neither has the Internet Archive. Given that Region 2 is all of the Americas and represents pretty much two fifths of all amateurs on planet Earth, that's a big hole.
<p>
There is some availability in Region 1 and 3, but those too leave to be desired. There does not appear to be any formal method of archiving or naming and the transient nature of the Internet all but guarantees that historic information like this is being lost at a high rate.
<p>
Even with those limitations in mind, there is plenty of information to be found. Let's look at Australia, for no other reason than that I was able to pull some of the historic information out of the bit-bucket.
<p>
You might be surprised to learn that there is much more change under the hood that far exceeds the band edges and segment changes. The Wireless Institute of Australia publishes the Australian Amateur Band Plan. Using the Internet Archive I was able to count that between November 2007 and November 2019 there were at least 25 different versions of that band plan published, for example in 2008 alone there were at least five different versions.
<p>
I managed to download 11 of those band plans which show the introduction of the 2200 meter band, the 630 meter band, changes to mode frequencies, DX frequencies, the allocation of emergency frequencies, changes to FM bandwidth from 6 kHz to 8 kHz on bands below 10m, the formalisation of WSPR frequencies, JT65, FT8 and JT9.
<p>
Now I must point out that the information I'm presenting here is incomplete. There are many more changes, just in VK alone. I'm relying on the Internet Archive which only sampled the WIA website 162 times between March 2008 and January 2020. Within those pages there were only 11 copies of the actual band plan and I've only compared three of them, August 2009, March 2015 and October 2019, and of those only a few changes that stood out.
<p>
And this is for Australia alone. This is on the HF bands. I've not even looked at the veritable feast of changes associated with the VHF and UHF bands, let alone the cm, mm and higher bands.
<p>
Even with this massive disclaimer, my point should be pretty clear. A band-plan is a living document. It changes regularly. Likely much more often than you realise.
<p>
I'll leave you with one burning question.
<p>
When was the last time you got yourself a copy of the band-plan? Seriously, when was it?
<p>
I'm Onno VK6FLAB
Listen:
Where do you start?
Foundations of Amateur Radio
<p>
So, you've got yourself a license, or it's coming but you're waiting for the regulator to get the administration done and for your payment to go through. The excitement is building, you're itching to get started and you've told your family and friends what your new callsign is.
<p>
Then the day arrives. Your callsign is allocated, it's paid for and you're allowed to call yourself a licensed radio amateur, a member of the community, a part of history, the next thing in radio.
<p>
Now what?
<p>
Where do you start on this adventure of a thousand hobbies in one?
<p>
The truth is that you already did. Look behind you. You have a license, a callsign and you've found the community, well, at least some of it. How do I know that you found the community? Amateur Radio is a secret, known only to those who bounce into it. That bounce is where you found the community.
<p>
Like any community you'll find people you like and people you don't. People who share your interest and people who are doing things that make your head explode.
<p>
That said, is there any sage advice that I can share with you on your journey?
<p>
I do, but, you're not going to like it. In fact until you've been an amateur for a little while you're possibly even going to hate my advice. I know, hate is a strong word. If it's not all black and white for you, you're going to think I'm chickening out in giving you advice.
<p>
Wanna hear it?
<p>
Start somewhere, anywhere.
<p>
Let me say that again.
<p>
Start somewhere, anywhere.
<p>
One of the most fundamental aspects of this hobby is that it's driven by your personal exploration, your journey, your imagination and your adventure. It's entirely up to you to decide what you like and what you don't.
<p>
I know that there are those who think that advice should come in the form of buying a radio, erecting an antenna and getting on-air. For many that's a journey worth doing. For others that's the beginning of the end of the hobby for them. If you're unsure which of the thousands of activities you'd like to do, since you don't know what they are, I'll tell you a secret.
<p>
Neither do we.
<p>
Seriously. There are so many things to do in this hobby that not a day goes by that I find a new thing to do and look at. A new toy to play with, or a new adventure to embark on. This morning I realised that the antenna design and build I've been working on represents roughly 600 million different variations. If I did those manually, taking a generous 10 minutes per set-up, I'll be here for nearly 35 years, 8 hours a day, trying another set-up. Clearly my hobby now includes automating antenna modelling.
<p>
My point is that there are so many different aspects of life, the universe, and everything that intersect in some way with the hobby of amateur radio that there's bound to be several that you can think of right off the top of your head. You might immediately be dismissing them as foolish, but if we all did that, nothing would ever happen.
<p>
If you're looking for ideas, that's a whole different thing. Of course the nearest search engine is a possibility, but I do have to confess, it's a dogs breakfast. Another is to visit your local club and see what others are up to. You could watch YouTube videos or listen to podcasts or read articles. All these are options to get suggestions.
<p>
Ultimately, the whole point of this hobby is that you embark on your own adventure, start on your own journey, down your own yellow brick road. If you think what you're proposing intersects with amateur radio, you're right!
<p>
That's not to say that there's no benefit to be had from engaging with others, far from it, just that you are the chief architect of your destiny. You're in charge.
<p>
So get to it. Go do something, anything. While you're at it, document the adventure. One day you'll be glad you did.
<p>
I'm Onno VK6FLAB
Listen:
What does Amateur Radio mean to you?
Foundations of Amateur Radio
<p>
Over the years I've been asked what the hobby of amateur radio is all about. My response has evolved over time, but it started with the lure of simple point-to-point communications. The antidote against such an example is that a mobile phone does that and more. Of course if you're already in the hobby you know that there is a massive difference between the two, but if you're an onlooker that is not nearly as obvious.
<p>
There are other problems with an answer like that. It doesn't cover the spirit of the hobby, the intent, the reach, or any of the other aspects of our pursuits that keep us all coming back for more.
<p>
I was asked recently to provide a credit to a fellow amateur for providing inspiration for an episode. Since then I've reflected long and hard about the nature of inspiration and what causes me to contribute and participate.
<p>
The reality is that my inspiration comes from all manner of nooks and crannies, from articles I read, videos I watch, discussions I have, activities I participate in, builds I make and emails I exchange. Not to mention friendships, random comments, shower thoughts and flights of fancy.
<p>
My understanding of our community of this hobby continues to evolve as I participate and contribute.
<p>
I think that underlying all of this is the expansion of my mind, my interests, my exposure to new things is what makes amateur radio such a massively interesting activity.
<p>
When I started I had no inkling that between learning how to solder and what a Fourier transform is lies this immense field of individual and community activity. What other hobby has the ability to link astronomy, moon, camping, community, planning, building, drilling, sound, language, antennas, internet, computing, valves, maths, propagation, mapping, transport, emergencies, physics, competition, camaraderie, satellite, soil, ionosphere, sun, batteries, old, new, invention and exploration?
<p>
In addition to the technical aspects there's the whole library of human interaction, teaching, learning, giving and receiving, socialising, friendship, discussion and debate to scratch the surface.
<p>
In amateur terms I'm still a babe in the woods and the more I learn the more I realise that this is likely to continue for the rest of my life.
<p>
For me, amateur radio is the binding force between interests. It's about wonder, curiosity and inspiration. It's about trying and failing, about testing and learning, about thinking and doing.
<p>
The magic for me is that you can do this at any level. As a 10-year old with a freshly minted license, or as a 90-year old with a twinkle in your eye. You can approach this as a scientist, or as an educator, as a submariner, or an accountant, as a truck-driver or a boiler maker, from young to old and anywhere at all, amateur radio is just plain interesting.
<p>
As for giving credit. I'd like to credit you for your contribution, for your participation and for your excitement.
<p>
Keep up the wonder and continue to make this community your own. In the end amateur radio means different things to different people.
<p>
What does amateur radio mean to you?
<p>
I'm Onno VK6FLAB
Listen:
Lamenting the decline of the hobby.
Foundations of Amateur Radio
<p>
During the week I received an email from a fellow amateur who described that they were feeling deeply disturbed by the decline of the core knowledge underlying the education and certification of today's new amateurs. This is a topic I've covered previously and some of what I'm about to say will touch on things I've said before.
<p>
I come from a long background in information technology. My first introduction was around the Motorola 6502 processor in the early 1980's. At that time a computer with 5 kilobytes of memory was a big deal. I learnt to harness every byte and nurture every bit. I learnt machine-code, BASIC, Pascal and Modula-2, which went on to form the basis of my current profession.
<p>
The reason I raise this is because there are many parallels in the evolution of amateur radio and the evolution of information technology.
<p>
For many years I lamented the dumbing down of the skill-set associated with newly fledged computer graduates. In a nut-shell, hand-coded would always beat Java. I held that view for a long time, until it occurred to me that in the big picture it didn't matter.
<p>
Let me elaborate before you start jumping up and down.
<p>
In computing, every two or so years, everything doubles, speed, memory, bandwidth, etc. The price pretty-much stays the same.
<p>
This means that the inefficiencies introduced by "high-level" languages like Java result in very little in the way of performance loss, but in return the actual process of writing new software accelerates. This means that you end up with more functionality, quicker, at the cost of less efficient code. That's a pretty reasonable trade-off.
<p>
If that example doesn't speak to you, it's the difference between rolling out turf from the back of a truck to construct a new golf course and teeing off in days, compared to spending a week planting grass, from seed, nurturing it and waiting at least two months until you might consider playing a round.
<p>
Does a golfer care if was rolled turf or planted seed?
<p>
A similar thing is happening in our hobby. The advent of Software Defined Radio creates a new category of experimentation. The component count is reduced by several orders of magnitude, in return for functionality built by way of software and maths.
<p>
Of course that means that the new amateur of today has no idea in the operation of a valve and only limited understanding of a transistor, but in return they can create new modes such as WSPR, JT65, CODEC2 and the massive evolution of other digital experiments, and they can do that with tools unheard of 5 years ago, let alone 50 years ago.
<p>
I am an example of an amateur who knows of the existence of a valve and I have a rudimentary understanding of how it works. I am seriously considering building my own Software Defined Radio, from scratch.
<p>
I understand that this might not be something that comes easy and may even be seen as detrimental to the hobby, but I dare say that the introduction of the valve to a spark-gap operator caused the same experience, let alone the introduction of the transistor, the integrated circuit or the explosion of cheap single on chip systems that can be had for cents in the dollar.
<p>
The essentials still remain. For example, right now I'm working on an antenna. It involves sourcing nuts that seem to be made from unobtainium, even though they are completely standard in our community and have been for longer than I've been alive.
<p>
The self-learning of our hobby, the exploration, the investigation, the curiosity will endure. What we're going to be playing with tomorrow is not going to be anything like what we were doing yesterday, and I'm OK with that.
<p>
That our hobby is changing is unmistakable. That's true for every human endeavour ever. I don't agree that there is a decline, nor do I think we've lost more than we've gained. I think the future of our hobby, our community and our pursuits is strong and bright.
<p>
I'm Onno VK6FLAB
Listen:
How did you get here?
Foundations of Amateur Radio
<p>
During the week I celebrated my ninth birthday. You might think that I'm quite eloquent for a nine year old and you'd be right if it was related to how I came to be born. My ninth birthday as an amateur appeared in my diary unexpectedly on a Monday and I took the liberty of telling a few people.
<p>
On one forum it started a wonderful series of comments from amateurs and would be amateurs about their experience coming to our community. I've shared mine before, so instead I'd like to share some of the stories that truly show just how diverse our amateur friends really are.
<p>
<p>
Floyd KK3Q says: My Dad was into CB radio (back when it wasn't so bad) and I was his antenna guy. He had black lung so I was the one who took down and put up his antennas for him. In the process I learned a lot (ask me later about a "smoke poles" and "buried 12V batteries") Well, Dad and I got into the illegal SSB frequencies and one night we visited one of the locals who happened to be using a Kenwood 520 on 11 meters. One look at that rig and I was in love. I never heard of ham radio and when I asked about it the owner said the radio was a "ham" radio and you needed a license to run one. Which she didn't have by the way. So I says, "Maybe I'll get myself a ham license and a rig like the Kenwood." She laughed at me, "You're just a stupid truck mechanic, you'll never get a ham license."
<p>
I never run from a challenge, skipped over Novice and got my Tech, wanted on 20 meters so under incentive licensing I had to upgrade to General which meant 13WPM CW and me partially deaf. Next I wanted SSTV but you had to be Advanced class so I upgraded. Finally I lusted after a short call sign so I upgraded to Extra back when 20WPM CW was still required. Been a nice run, learned a LOT from a lot of elmers.
<p>
Floyd has been a ham for 42 years.
<p>
<p>
Bill WK2KX has been a ham for 33 years. Will be 34 this January. Licensed at age 11. He goes on to say:
<p>
My dad and I did it together, but most of my family are licensed as well. My grandfather started it. His main claim to fame is that he served as general Eisenhower's radio man during ww2 for about a month. Now I have both my parents, a bunch of cousins, aunts, uncles, etc who are all licensed - enough that I've considered creating a "worked all (our last name)s" award, haha.
<p>
<p>
Tyrell KD7TKJ turned 18 as an amateur in September.
<p>
My stepdad wasn't a ham, but one of the kids he grew up with was... And my stepdad told me a story at a young age about how he and this neighborhood kid would go to the auto wreckers to pick up scraps to build radios out of, and then use said radios to talk to Australia... The details of said story really were never complete, and I've never met anyone since that claimed to have built a radio from car parts... But it was enough to get me to (get my mom to) get the ARRL Now You're Talking book and get licensed. I've been addicted to this more than any money making Enterprise ever since.
<p>
<p>
One amateur writes: I got my license 48 years ago. In high school, every day I'd pass a door with no window, just a sign "W2CXN". When I got the courage to knock, I was met with a person I knew liked his job. So happy to help. I remember thinking, how cool is that?
<p>
<p>
Peter KD2TCQ has been an amateur for 4 days and got interested because of packet radio as well as the ability to do on HF (which he needs to upgrade to do via phone but he's studying for that)
<p>
<p>
Ron K7UV says: I'm at 62 years and was licensed at age of 12. My dad and I built two receivers together and I wanted to do more than listen... the rest is history. Yup, I go way back before transistors and computers and remember cycles, mmF, aerials and condensers.
<p>
My original Hammarland receiver had around 13 tubes, the transmitter had 6 tubes plus the 2 meter converter had 4 tubes and my SCR522 had at least 7 tubes. It kept my bedroom quite warm in the winter and sweltering in the summer when there was no air conditioner, just fans.
<p>
The weird thing... I miss those days, maybe it's just my nostalgia kicking in. But radio and my interactions with my father were essentially what led me to radio.
<p>
<p>
Matt KD2MGM says: I suppose We're only 3. My brother and I put CB radios in our trucks in the summer of 16' but we quickly realized living out in the country that there weren't really any people on the air waves and that 4 watts wasn't enough to talk over the hills to each-other. These days we are not super active but still hop on the air once in a while.
<p>
<p>
You can find all these stories and many more on the amateurradio sub on Reddit.
<p>
For me, reminiscing over how you came to be part of this amazing community brings us all together. Our stories are not that different, we're all cut from the same cloth. Curiosity killed the cat, but it just makes amateur radio stronger.
<p>
How long have you been an amateur and what got you in the door?
<p>
I'm Onno VK6FLAB
Listen:
The SDR earthquake will change our hobby forever
Foundations of Amateur Radio
<p>
In the early 1990's when I was a broadcaster I would come into the studio and prepare my show. That involved hours of preparation, but on the technology side it involved vinyl records, reel-to-reel tape on open spools, looped tape on cart, running edits and razorblades. If you're not familiar, a running edit is where you're playing the tape at normal speed and you hit record at just the right moment to replace the content. Of course that also requires that the thing you're recording is synchronised. Imagine yourself with four hands and three ears and you'll have a good idea. Razor blade edits required that you mark the tape where the audio started, chop the tape at that point and stick it to another piece of tape. The joy of having sticky tape, razorblades and audio tape strewn around the room and hoping that the tape didn't let go when you transferred the audio to a broadcast tape.
<p>
If you wanted to play a song at the right time, you had to start it by putting the needle on the record, spinning the platter until you heard the song, then stopping the platter, winding back half or three quarter turn from where the audio started, depending on the speed and torque of the turntable, and then when you hit play, you'd have about half a second until the music started.
<p>
At the beginning of the 1990's that was how it was done.
<p>
Then compact disc came in and we could cue up a song and hit the go button and get almost instant sound. You could change tracks at the turn of a dial. Vinyl records were phased out pretty quick.
<p>
In 1993 I switched radio station and instead of reel-to-reel we used DAT, or Digital Audio Tape. It had the advantage that there was no discernible loss of audio quality as you copied material, but there was no editing, since the bits on the tape needed to be aligned and you just couldn't do that with most of the available gear. The start-up delay was horrendous too, several seconds if I recall. A lifetime of dead air if you got it wrong.
<p>
You might be wondering why I'm going down memory lane like this?
<p>
The reason is that something changed, fundamentally, almost overnight.
<p>
In 1995 Microsoft launched Windows 95. It was in August and as the local computer show I organised a competition to give away a copy of Windows 95. I edited my competition stinger, a 15 second and a 30 second promotional audio segment, entirely on my computer. Using SoundEdit 16 on my Macintosh computer I could overly tracks, add voice-overs, move sound tracks around, add dozens of tracks, change the left and right channel independently, amplify or delete specific beats, all things that were completely impossible using the gear in a radio station at the time.
<p>
When I brought my stinger into the station managers office on my laptop computer, the earth shifted. Overnight everything changed. At that point radio stations around the globe started the race towards entirely being run from hard-disk. The digital revolution hit broadcast audio.
<p>
That's almost a quarter century ago, but that change cannot be overstated.
<p>
I think that in amateur radio we're looking at the same kind of change with the same level of impact.
<p>
Today you can go online and buy a NanoVNA for less than a hundred dollars. This device, a touch-screen driven tool, allows you to measure electrical circuits. For example, you might connect an antenna and measure the impedance of that antenna. If you connect a reference antenna to the second port, you can even measure radiation patterns.
<p>
Think about that for a moment.
<p>
You can measure a radiation pattern. That means that there is something that radiates.
<p>
Does that sound familiar?
<p>
Perhaps like a transmitter?
<p>
So this NanoVNA is essentially a transmitter and receiver in one box, currently runs up to 900 MHz, but the next version is already in the works and it's slated to manage 3.5 GHz, for the same amount of money.
<p>
So, a 3.5 GHz transceiver for less than a hundred bucks.
<p>
If you look at the internals of a NanoVNA, you'll notice that it's got much of the same bits as a software defined radio, because it is a software defined radio. Thanks to modern integration, at a component level it has significantly less complexity than the early 1980's microcomputers I grew up with like the Commodore Vic 20.
<p>
Yes, I know, it's not quite a radio. There's different filtering, different software, no audio input, or output for that matter, no Morse key, it doesn't do FT8 or some other fancy mode, but guess what, it's all software. The parts of this device aren't complicated, they're cheap, simple to program and I don't think it's going to take long before we see a new explosion of software defined transceivers that are begging to be used by radio amateurs around the globe.
<p>
We live in exciting times would be the understatement of the year.
<p>
I'm Onno VK6FLAB
Listen:
Morse Code and You
Foundations of Amateur Radio
<p>
With the growing availability of new ways of communicating across the globe, from digital voice such as CODEC2, through weak signal modes like WSPR, JT65, MSK144 and FT4 to name a few, with Internet linked radio such as Brandmeister and DMR and the newly granted access to all Australian amateurs to all those modes, it's easy to overlook the one mode that started this adventure.
<p>
Morse Code.
<p>
It's no longer required to obtain your amateur license, so if that was putting you off from getting your license, you can breathe easy and get right to it.
<p>
Among all the shiny new modes Morse Code continues to hold its own and for good reason. It's simple, reliable, has an amazing signal to noise ratio and if you're driving in your car and you're stuck without a Morse Key, you can always just whistle into your radio.
<p>
If you've been following my journey through the hobby you'll know that I've been attempting to learn Morse Code. For a while now. It's been a challenge, more so since I spend less and less time in a car and more and more time behind my keyboard appeasing my clients. That's not to say that I've forgotten, just that what I've tried so far has eluded success.
<p>
A little while ago I received an email from a friend, Shaun VK6BEK who let me know that there was a discussion happening on a mailing list he was a member of and in that discussion I cracked a mention. Being the shy and retiring type I had to have a look for myself. To read the message I had to join, which is fine, since Charles NK8O has been bugging me to do that for years, well perhaps not bugging, perhaps keying me - hi hi. Turns out that the Straight Key Century Club, the SKCC, was having a recurring discussion about the topic of Head Copy or Head Reading.
<p>
To give you a sense of what that is, consider what I'm saying to you right now. It doesn't matter if you're reading this in an eBook on your Kindle, reading it on an email or online, listening to it on your local repeater, or via your favourite podcast player, for each of those the same process is happening.
<p>
You are not absorbing individual letters or sounds, but getting the meaning from the entire structure of a sentence. For uncommon words you might need to calibrate your brain, but for the most part you're just bobbing along understanding what I'm saying.
<p>
In essence you're doing the equivalent of Head Copy.
<p>
In Morse Code the same can be achieved. Ultimately it's a language, a tonal one, but a language none the less. Hearing the individual dits and dahs, followed by letters, words and sentences, eventually you'll get to a point where it all just flows.
<p>
I speak a few different languages, a curse or a blessing depending on your point of view. It means that I've become exposed to how language is built up. Initially when you hear a new language your brain is trying hard to figure out where the individual sounds belong, which sound belongs to which word, how a word begins and ends, how you make a plural, all the things you take for granted after you've learnt a language.
<p>
In Morse that is no different.
<p>
Within that context of discussing Head Copy, Gwen NG3P mentioned that she used the text edition of this podcast to convert into a Morse Code MP3 file so she could learn to hear Morse and bring them with her on her mobile phone.
<p>
Gwen and I had similar aims. In the past I'd done the same with a book, Huckleberry Finn if I recall, as well as random letters and also the ARRL Morse practice downloads, but nothing seemed to work for me.
<p>
For Gwen my podcast was an obvious source, so much so that I completely missed it, since they are short and on the topic of amateur radio. The language in use is likely going to be things that you'll hear on air and there's a smattering of callsigns, so all good.
<p>
Long story short, I spent last week converting all 454 episodes of the podcast to Morse Code for your Head Copy practice enjoyment. They're encoded at 25 WPM, or Words Per Minute and the tone is 600 Hz. I even put them online and made it possible for you to add them to your podcast player.
<p>
Best part?
<p>
I now get to hear Morse Code at a pace that I'm looking for, on a topic that's relevant and I have been receiving plenty of emails from others who are just as excited as I am.
<p>
You can find these episodes on the podcast homepage at http://vk6flab.com. Let me know how you go.
<p>
I'm Onno VK6FLAB
Listen:
What's in a Whisper?
Foundations of Amateur Radio
<p>
A while ago I set up a WSPR, or Weak Signal Propagation Reporter at home. Before I go into the details, WSPR is an amateur radio protocol that allows stations to transmit their callsign, location and power level and for receivers around the globe to decode those and upload the results to a central database. It's a great way to see what you can hear and what propagation is like.
<p>
A couple of months ago the regulator changed the Australian License Conditions Determination, the rules of engagement around amateur radio and now all licensed amateurs in Australia can even set-up a transmitter although I haven't yet. Receiving is plenty of fun and anyone can do that.
<p>
Initially I used a piece of Windows software to track the contacts but to me it was like ordering a courier with an 18-wheeler to pick up a postage stamp. I looked around an found a piece of software that runs nicely on a single board Raspberry Pi computer. The software is called rtlsdr_wsprd, it's a mouthful, but it works nicely on a Pi with an RTL SDR dongle. The dongle I have is capable of using all HF frequencies up to 1766 MHz, so I can technically hear the 23 cm band, though I haven't actually heard any stations there.
<p>
I created a list of all the published WSPR frequencies and I listen to a frequency for fifteen minutes, pick another frequency at random and do it again, all day, every day. My log for this installation goes back about eight months and I get about a hundred contacts every month or so.
<p>
You might think that's a lot of contacts, but really it's not. The antenna is indoors, it's under a metal roof and while it's on the second floor, it's far from ideal, but it works surprisingly well.
<p>
What have I learned from this experience?
<p>
I've heard 36 different stations, across 11 countries and 23 grid squares, the furthest was G0CCL, a club station in Cambridge in the United Kingdom which was transmitting on 20m with 5 Watts. I heard it 14750 km away.
<p>
There are plenty of other things that I can extract from this. The most popular band is 20m, it accounts for nearly 70% of the contacts I heard. Surprisingly, I am also hearing contacts on 80m, as well as on every other amateur band that my receiver can hear. The 6m band is pretty popular too, nearly 13% of the stations I heard.
<p>
For my receiver, between 4am and 6am in the morning was the best time to hear something, together they account for just under 20% of the contacts. Locally the worst time is 8am in the morning.
<p>
From the data I've collected, April and May were the most active, accounting for nearly 70% of the contacts.
<p>
I must point out that the log is not continuous, there's gaps when the logging station wasn't switched on and when I was switching antennas and locations, so using the statistics I've given you here for your own station are probably not going to work quite the same.
<p>
The WSPR mode isn't perfect. It will happily decode rubbish and report on that, so I've manually filtered out the bogus information, like for example a grid square XI97LK, or callsign 3KE/21XWK, where neither the location or the prefix are real.
<p>
I can tell you that I was surprised that my station can hear 80m on the little telescopic rabbit-ear antenna supplied with my dongle. That same antenna is also fine at hearing 6m, so I'm pretty happy with that.
<p>
One thing that this little experiment reveals for me is that a cheap dongle is a perfectly fine way to start playing with a limited budget. It offers the opportunity to explore the RF spectrum using modern tools and techniques. Much of what I describe is absolutely possible with a traditional radio. Originally I had my station set-up like that. It consisted of my Yaesu FT-857d, a 12 V power supply, a CAT cable, an audio interface and a computer.
<p>
In stark contrast, my current set-up consists of two things. A Raspberry Pi with an RTL SDR dongle plugged in.
<p>
While this set-up cannot transmit, neither could I at the time. Since then there have been advances in both. There are all-band WSPR transmitters for a similar cost to a Pi and a dongle. Power it up, configure it and you're good to go. I'm eyeing off that as a future project, since it's perfect to use to see what bands are open for your station at any given moment.
<p>
If you've never had a go, you should. I've documented how my monitor station works and you can find it on the projects page on my website at vk6flab.com.
<p>
WSPR is a really nice way to get into many different aspects of our hobby and the barrier to entry is your imagination.
<p>
I'm Onno VK6FLAB
Listen:
Putting a radio in a car.
Foundations of Amateur Radio
<p>
Putting a radio in a car.
<p>
As you might recall, most of my radio activity is done away from my shack. I tend to operate portable, camping, sitting on a jetty or using a picnic table while a BBQ is going nearby.
<p>
For me operating with my car as a mobile base made more sense than trying to cram an antenna in a home with little or no garden.
<p>
Putting a radio in a car can be as simple as bringing a hand-held and hanging it from the rear-view mirror, or it can involve a mobile phone mount that allows you to clamp it in place.
<p>
Pretty soon you'll want to have an antenna on the outside of the car, so then you start figuring out how to make it go through the car without needing to drill holes and sparking the ire of the other users of the car.
<p>
Not long after that you'll want to charge it, then the microphone will become inconvenient, changing frequency, using it for more than talking on the local repeater.
<p>
Eventually you might well get to the point that a hand-held is no longer appropriate.
<p>
Without telling you which radio to buy, since there are many different ones to choose from, with different specifications, different pricing, different functions and different sizes, there are plenty of roadblocks to radio bliss in the car.
<p>
The very first one is: Where to put the radio?
<p>
If your radio has a detachable front, that is, the buttons and display can be separated from the main body, you'll have more options, but if that's not possible, you'll likely need to find somewhere near and preferably visible to where you'll be using it.
<p>
There are transceivers that fit into a standard car radio opening which might come in handy if your car comes with all manner of bezels and curves. You might find a spot in the centre console, or overhead.
<p>
If you can put the transceiver in one spot and the head in another, then you can put the radio in any little hidey hole, for example, under the passenger seat, or in the luggage compartment, in the glove box, or behind the drivers seat.
<p>
When you are looking for a spot, consider how you're going to get electricity to it and how you're going to connect the antenna. You'll likely need to connect the power supply wire directly to the battery, which might determine how the power gets into the cabin of the car.
<p>
If you can drill holes in your car, you'll have extra options, but consider that you'll need to protect the wire that goes through those holes and you'll also need to protect the steel, given that once you drilled that hole, it's no longer protected by paint from rusting.
<p>
The same is true for the antenna. Can you use an existing path, or do you need to make a new one? If you put the radio in the luggage compartment, can the antenna lead exit that and what happens if it rains?
<p>
In my set up I have an all band radio, it does HF, VHF and UHF, but I didn't want to have multiple antennas on the car. The radio has multiple sockets, so I used a coax switch that's connected to an antenna mount on the rear of the car and ran two lines back to the radio, so I can switch between HF and VHF. Of course I need to swap out the antenna, but I'm not switching whilst I'm driving, so that's no problem.
<p>
Other things to consider are what noise comes from the car. I don't mean the zoom-zoom noise, I mean the noise from things like the alternator. How will you deal with that? What about grounding? How will you make the ground plane of the antenna? Can you use braid to connect the various panels of the vehicle to each other?
<p>
If your mount is temporary, like for example a magnetic mount, how will you protect the paint work? Can you clamp something across an edge, or will you need to drill a hole?
<p>
If you're at all unsure, then try some set-ups. Run a temporary power supply through a door, figure out where stuff goes. Look at what your friends have done, test it by going out, park somewhere and try to use it for real.
<p>
It can be daunting to set-up a car, but it is very rewarding and it's a great way to get used to the many aspects that are involved once you dive into this hobby.
<p>
I'm Onno VK6FLAB
Listen:
Where is North?
Foundations of Amateur Radio
<p>
The other day we were aligning an antenna for a contest. It had slipped on the rotator pole during a recent storm and when the rotator was set to zero it was pointing somewhere south east. Not ideal if you want to point your antenna at a particular station.
<p>
The topic of the direction of north came up. There was vague hand-pointing, some mobile phone compass magic performed and north was arrived at. I asked if that compass took into account magnetic declination which in turn was met with blank stares.
<p>
So, what is magnetic declination and where is north?
<p>
It's likely that in school your first physics lesson was around magnetism. Playing with magnets is an easy way to start the conversation around science. One thing you learn in school is that opposite magnets attract. A north pole to a south pole and so on. A compass is a simple magnet with a north and a south pole. So, the north pole of the compass is attracted to the south magnetic pole of the Earth.
<p>
This means that the Earth's north magnetic pole is currently at the bottom of the Earth. Also, while we're on the subject, the magnetic field lines that leave a magnet are defined as being the north pole of that magnet. So on top of the planet the magnetic field lines enter the Earth and at the bottom of the planet they leave the Earth.
<p>
That definition of north and south was the first to be used and it was pretty successful in getting sailing ships all around the globe. Since then the definition has changed into defining the poles as the points around which the Earth rotates on its axis. The north pole is the one on your left as you face the rising Sun.
<p>
So, the north pole that you and I talk about in day-to-day conversation refers to an imaginary point where the Earth rotates around you and you stay still - ignoring for a moment that the Earth is hurtling around the Sun and the Sun is moving around in the Solar System and the Solar System is moving in the Milky Way Galaxy and its moving inside the Universe, turtles all the way down.
<p>
In case you're wondering how fast you're moving while you're standing still, it's in the order of 360 km per second in relation to the cosmic background radiation. By the time you've finished this you'll have moved about a hundred thousand kilometres from where you started.
<p>
The subtle difference between the definition of north being related to the magnetic pole and the rotation axis means that there's a difference where your compass points and where north is. You probably already knew this.
<p>
You might not know that the amount of distance between both the magnetic poles and the rotation poles changes over time. The magnetic poles of the Earth are constantly moving. That's pretty straight forward, but there's more. The Earth's magnetic field isn't pretty. It's not all straight lines and unicorns. It's messy, very messy. And the mess is moving. Normally there's a new map published every five years, but sometimes that's not enough to account for the movement. For example, early in 2019 a new map was published out of sequence to account for changes that were larger than expected.
<p>
Why the map you ask? Because field lines are not straight. You'll find all manner of weird shapes and swirls. This means that where ever you are on Earth, your compass is pointing in a different direction, because it's not pointing at the magnetic pole, it's aligned with the magnetic field line which could be as much as 20 degrees off, in either direction, so 40 degrees error could make you completely miss Australia as you're sailing around the planet.
<p>
If this is beginning to sound a little familiar, you might consider our Sun. Every sunspot is a magnetic pole. They come in pairs, a magnetic north pole where the magnetic field leaves the Sun and a magnetic south pole where it enters the Sun. If you've come across the impact of the Sun on radio communications and the ionosphere, you'll already know that the Sun is a turbulent place. Sunspots come and go, they move around, there's cycles within cycles, solar minima, maxima, pole reversals, lots of stuff that makes this a variable feast.
<p>
The Earth is doing this too. Not as fast, not as hard, not as big as the Sun, but measurable and a rich source of research for Geophysicists and Geologists, since we can even figure out that the magnetic field on Earth reverses itself, has done many times, just like the Sun.
<p>
So, next time you get the question, where's north, check out the magnetic declination map for your location, you might be surprised where your compass is pointing, it's almost certainly not north.
<p>
I'm Onno VK6FLAB
Listen:
In pursuit of a challenge
Foundations of Amateur Radio
<p>
An interesting question came up the other day. It's there such a thing as a solo contest? At the time I answered with examples like talking to a hundred countries to achieve the DXCC, or doing that on every band. I gave other examples too, but today I'd like to come at this from a different angle.
<p>
When you go fly fishing, you typically stand in cold water trying to tempt a fish into taking your lure. If you are in the right spot at the right time with the right bait you might be lucky and achieve momentary bliss with the capture of a fish.
<p>
That moment, the peak of achievement when the fish bites, that's a moment for you and you alone. Of course you'll be able to brag about it later and bask in the glory of your achievement, but the moment itself is a solitary experience.
<p>
Many aspects of amateur radio are exactly like that.
<p>
The circumstances are not even that different. Instead of standing in cold water, you're having your eardrums assaulted by noise. Instead of a line you have an antenna. Instead of a lure, you have your voice, but the same thrill happens when you hear your callsign being said by the other station. Calling back and forth with the exchange is much like fighting a fish. The bragging is no different.
<p>
Of course amateur radio isn't actually fly fishing, but it's close.
<p>
One of the things that you can do with amateur radio is achieve the bliss of success together with friends. You can compete in a contest together and share the missed opportunities, the misheard callsigns and what ever else chance throws in your way. Yes, I know, in fly fishing you can participate in the World Championships as a team, but generally it's a solitary experience.
<p>
Oh, I should point out that my relationship with a fishing rod is an unhealed one. At the age of ten or so I managed to catch a fish in the local canal. At age 36 I caught a tiny fish on a safety pin in a pool at the base of a waterfall in the Kimberley. Typically I carry a fishing rod around into the bush with a lead weight to hoik it through a tree so I can pull a wire antenna up, so if there's any inaccuracies in relation to my dissertation on fly fishing, please don't hesitate to let me know.
<p>
I've said this before. Amateur radio is lots of different things. It's a pursuit of technology, of excellence, of challenge, fun, victory and it's about having the experience.
<p>
You can do this on your own and feel the amazing joy of making a contact, or you can do it with friends. Ultimately the choice is yours.
<p>
Which ever one you pick, how you play is up to you. You can decide to see what comes along, or you can set out to make something happen. There is no right or wrong way, nobody to tell you that you must this or should that, it's entirely your decision to make.
<p>
I like, actually, I love trying to get better at whatever I do. Talking to people, crossing the street, building an antenna, making a contact, winning a contest. I love trying new things, having new experiences, and seeing what others do differently. That's my make-up, it's me.
<p>
If you want ideas on what to do, feel free to ask, but expect me to be interested in how you go. If you tried something new, share your experiences and tell your tale. I really don't mind if it failed. I'd much rather hear that you tried, rather than gave up before you started.
<p>
So, what's your next adventure?
<p>
Perhaps you have a waterproof radio and you want to bring it when you next go fishing ...
<p>
I'm Onno VK6FLAB
Listen:
First Solo
Foundations of Amateur Radio
<p>
The other day I looked in my diary and noticed that it was the anniversary of my first solo flight. If that's not familiar to you, it means I got in an aeroplane on my own for the first time, taxied to the end of the runway, made a radio call to warn all the other pilots, took off, flew a circuit and landed safely. All the essentials for flying a plane.
<p>
It occurred to me that there was a period of preparation associated with that flight. I did training, I practised, I got my gear in order and then after all was ready, I did the actual flight.
<p>
In a technical hobby like Amateur Radio it's easy to get stuck in any of the steps leading up to your first transmission. It's just as easy to get stuck getting ready to do a contest, activate a digital mode, climbing a SOTA peak. Each of those activities are part of our hobby and doing those can provide you with a sense of achievement, a measure of success and ultimately the confidence to continue in this hobby.
<p>
I've said before that there is a contest on pretty much every weekend, if not quite every day. People who participate in those contests do so for a variety of reasons, from testing equipment, to getting different countries in the log, to catching up with friends, to winning.
<p>
I'm a die-hard contester. I love the chase, love to improve on my performance, get better, do more, faster, etc. That's not to say that there are times when I use the opportunity of a contest to try something new.
<p>
At the moment I'm in the process of trying to figure out how I can record my voice into appropriate audio files so I can make the logging tool N1MM make all the noise on behalf of my vocal chords. Calling CQ for hours on end is not a good way to protect your voice and for those within earshot it's no way to spend a weekend listening to gibberish fill the house.
<p>
I don't know how I'll go. Admittedly I've left it a bit late for the contest at hand, but I'm going to give it a go. I doubt I'll achieve more than a dozen contacts, if any, but then that's not why I'm doing it.
<p>
My point is that you can, for any reason at all, participate in a contest. You don't need permission, you don't need to be asked, you can just decide to. When you're ready, when you feel the urge, when you think you can, or even if you think you can't, have a go. Today. Now.
<p>
Some fair warning. If you pick a busy contest, like say the CQWW, you'll find that there are plenty of other stations around. They too are having a go at what ever level they choose to. Some will be out to win and others will try to say hello and want a chat.
<p>
When you start you might feel the need to do lots of calling. Better use of your time is to have a listen and see what's happening. Check out the other operating techniques. Once you have the hang of it, try it yourself. It won't hurt, nobody will bite, though some might get testy if you jump on top of a rare station.
<p>
If that's all too much to try and it's a little too scary, find yourself a local net, a discussion, an on-air meet-up, and have a listen. Then, if the going's good, join in. Key your microphone and say your callsign. Take it from there.
<p>
Going Solo is something that every amateur you hear on air has done. It's time for you to do the same.
<p>
Now get on air and make some noise!
<p>
I'm Onno VK6FLAB
Listen:
World Wide Radio Operators Foundation
Foundations of Amateur Radio
<p>
The other day I accidentally learnt something new. I know, it's crazy, sometimes I surprise myself.
<p>
I received an email that announced an activity from something called WWROF, more specifically, the World Wide Radio Operators Foundation. It caught my eye, because it was announcing a webinar about an upcoming contest, as it happens the largest annual amateur contest, the CQ World Wide. The time zone for the webinar put it firmly during my sleeping hours, so I asked about the availability of a YouTube video after the fact.
<p>
Got an email back from Founding Director, Mark N5OT, and you'll be pleased to learn that there is in fact a video, not only that, videos going back to the dawn of the organisation with topics focused on Amateur Radio Operating.
<p>
There's information about Receiving Antenna Metrics; Constructing a Horizontal Waller Flag; Ethics in Contesting; RTTY or Legacy Digital Contesting; Solar Spot Cycles; Dayton Hamvention; High Performance Receive Antennas for a Small Lot; World Radiosport Team Championships; Contest University; Operating two bands, using synchronised, interleaved QSO's; Remote Multi-Multi Contesting; and more, much more.
<p>
To think that I didn't know this group existed and I've been here for a while, turns out, they've been around since 2009 when the foundation was created by a group of radio amateurs who saw a need for an independent organisation devoted to the skill and art of radio operating.
<p>
Their motto is:
<p>
"Dedicated to improving the skills of amateur radio operators around the world, utilising education, competition, advancement of technology and scientific research, promoting international friendship and goodwill, and preparing them to better serve society in times of communication need."
<p>
Gotta say, if it weren't for the fact that it's on a web-page that I don't control, that could have been written by me.
<p>
The WWROF puts contesting front-and-centre in the art of operating. They believe, and I agree, that amateur radio contests provide a means of testing operating skill.
<p>
So, what have this group of radio operators been up to?
<p>
Well, they administer the Cabrillo log format, support Contest University, support webinars on topics of interest to Contesters, created the Contester's Code of Ethics, Sponsor the World Wide Digi DX contest, are developing wideband recording systems, manage contest awards and donate equipment to young contesters and developing-country contesters, and finally they support the World Radiosport Team Championship.
<p>
So, if this leaves you thinking that I'm advocating that you should check out this group, at wwrof.org, you'd be right.
<p>
If you're looking for something to learn and YouTube is your medium, then check out the WWROF channel. Lots to see and do.
<p>
One thing that might not be obvious from my glowing reports is that this is for you at whatever level of contesting you find yourself, not only that, it's not about contesting per-se, it's about operating as a radio amateur.
<p>
For example, you'll find a discussion by Craig K9CT who describes how to plan your station, from finding land, selecting antennas to the layout of your shack. There's information about how to contest as a Rover Station by Rick K1DS. There's outlines of rules for various contests. Carl K9LA describes how to use Grey Line Propagation on the Low Bands, and Ed N4II talks about how to use 80m to get from Florida to the Cocos Keeling Islands around the corner from me, well 2932 km and that's 300 km closer to me than Sydney.
<p>
I should mention that I have no relationship with the World Wide Radio Operators Foundation, but given their purpose of existence, I endorse their efforts. Their address is wwrof.org.
<p>
I'm Onno VK6FLAB
Listen:
How to make contesting interesting to an audience?
Foundations of Amateur Radio
<p>
As you might know I enjoy doing contests, actually that's an understatement; I LOVE doing contests. I think that they represent an excellent way to learn about operating procedure, propagation, band selection, antenna direction, callsign recognition and dealing with adverse operating environments. In short, I think that contesting teaches you lots about amateur radio in a very short time.
<p>
That said, doing a contest, or learning from a contest is challenging and for a new amateur it can be absolutely daunting.
<p>
If you have the luxury of a club station, you're familiar with the following picture.
<p>
Bunch of people sitting around in the shack, one person operating the radio. If the operator has their headset on, the conversation in the shack will be about life the universe and everything. If the operator isn't wearing a headset, the conversation in the shack will also be about life the universe and everything with the radio blaring in the background and the operator initially asking people to keep quiet so they could discern that elusive DX station, frustration growing with every contact.
<p>
Being at your own station might not be much different. Replace shack with home and the people in the shack with your family and you get the picture.
<p>
If you step into that environment as a new amateur you'll get a sense of camaraderie, but little in the way of contesting knowledge. If you're lucky you might have someone point out what's happening, but quickly the conversation is likely to turn to other topics. It's hard to participate when you can only hear half the conversation.
<p>
Recently I did another contest. As I said, I love them, so why not? I invited two new amateurs to the party. They arrived separately at different times and had vastly different experiences. My first guest got to see the back of my head whilst I called "CQ Contest VK6FLAB", followed by "NK8O, you are 59020", then "104, CQ Contest VK6FLAB".
<p>
My second guest got to hear the whole contact.
<p>
"CQ Contest VK6FLAB", "NK8O" "NK8O, you are 59020", "VK6FLAB you are 59104" "104, CQ Contest VK6FLAB".
<p>
In both cases I was wearing a headset, but in the case of my second guest I'd finally achieved something that I'd been aching to achieve for years. I managed to combine the best of both worlds. The radio audible in the shack and the operator wearing a headset, at the same time.
<p>
My intent has always been to get this to work, but radio after radio, configuration after configuration, shack after shack, this seemed to be a doomed attempt at getting my fellow amateurs to understand why this was important and how we might implement this. One of the radios in the past had a Headphones plus Speaker option, but it wasn't ideal and as I recall, it handled sub-receivers poorly, not to mention the menu shenanigans required to actually make it work. The current radio in the club-shack is typical of radios today. Headphones or Speakers, not both. This radio has an Ethernet port, so there was talk of using Voice over IP and extracting it to multiple destinations. This conversation went on for a while.
<p>
I then hit on the idea of using computer speakers, tweaking them by clipping the wire that mutes the speaker when you insert headphones.
<p>
In the end, the solution was much nicer, much simpler and easy to implement for any radio with a headphone socket. I confess that I cannot believe it was this simple, but it was.
<p>
Get yourself a Y-adaptor. It's basically a headphone splitter. You can get them almost anywhere, supermarket, petrol station, electronics store, anywhere that sells mobile phone accessories to teenagers who want to share their music with their friends.
<p>
Plug the Y-adaptor plug into the radio headphone socket. Plug your headphone into one of the Y-adaptor sockets and plug some powered computer speakers into the other Y-adaptor socket. Set the volume on the radio for your headset as needed and adjust the computer speaker volume as required.
<p>
End result is an operator who can hear the contact and a shack that can teach a new amateur about what's going on.
<p>
Bliss.
<p>
Feedback from guest number two - this changed everything and he learnt a great deal after that.
<p>
Mission accomplished.
<p>
I'm Onno VK6FLAB
Listen:
Leave some bread crumbs behind
Foundations of Amateur Radio
<p>
About a year or so ago I received a message from a friend of mine. The message asked if I would have or could find a use for some amateur radio gear from their active amateur father who became a silent key. That started a sequence of events that leads us here, today. In the year that followed that message I became the grateful owner and archivist of an amateur shack that belonged to Walter VK6BCP (SK). Walter had two calls that I know of, VK6BCP, last logged on the DX cluster on the 5th of April 2012. His other call, from Switzerland, was HB9CAI, last reported on the cluster on the 23rd of February 2005.
<p>
The more I dig into Walter's collection of all things that make a shack, coax, connectors, boxes with spares, power supplies, odds-and-ends, the more I find a kindred spirit. I never met Walter, but he and I share the same sense of order. We sort things in the same way, we have the same kinds of things on hand and it's gotten to the point where it's hard to tell where his shack ends and mine begins.
<p>
Walter's shack contributed several radios, some of which I loan out to beginning local amateurs, I took one with me on a recent trip and I've been using one to run a weekly net to see how this particular radio works and what quirks exist.
<p>
One of the requirements to actually switching on that last radio brings me to bread crumbs.
<p>
I needed a power supply to make the valves glow - well, the digital display - but you get the idea. There was a suitable power supply on the shelf, but I had no idea when it was last switched on, if it worked, if it would set fire to my shack, what the state of it was. It looked near new, no scratches on the paint, bit dusty, but it looked as well loved as my own power supply, which is now coming up to nearly a decade old.
<p>
I picked it up and the power supply rattled. Never a good thing in a device that has no moving parts. On closer inspection I noticed that only four of the fourteen screws were holding the case together and it stopped me from plugging the thing in and turning it on - with a stand-by fire extinguisher at the ready - mind you, I might have been slightly exaggerating with the fire extinguisher.
<p>
I did what any enterprising radio amateur would do in that situation, I got out a screwdriver and extracted the four remaining screws and lifted the lid. I wasn't sure what I would find, but nothing prepared me for what was there, though Walter being Swiss should have.
<p>
Inside this lovingly maintained power supply I found a little zip-loc bag with ten screws. The ones missing from the case. This was the source of the rattle.
<p>
I also found a disconnected fan lead, actually, it had been purposefully cut and folded back.
<p>
Now why do you suppose that was?
<p>
For my money, Walter knew this power supply well. His power requirements didn't need a fan - truth be told, mine probably don't either - and to keep everything in one place and to remind himself that he'd made a modification, he'd done the smart thing, make it obvious that something had been modified.
<p>
He could have put a sticker on the case, but over time that would have faded. He could have carved his initials into the case and carved an instruction, but both of those would have reduced the aesthetics of the power supply and if his callsign ever changed, or if he reconnected the fan, he'd have to start again.
<p>
What I found was something that gave me pause to consider how you manage to document what you've done, not only for yourself, but for others who might stumble on your modification. I'm certain that Walter never considered that one day I'd be telling you this story and thanking him for his preparation, but that's exactly where we are.
<p>
You might come away from this wondering what the point was of all this?
<p>
The point is, you can prepare your shack for events that might not happen. You might lose your memory, become a silent key, or have a beginner borrow your kit. You'll never know what it will be. What you can do is make it possible to discover that something has been changed. Walter could have just as easily put all fourteen screws back in and I would have never been any the wiser. I might have thought that the fan only came on under load, instead of not coming on at all, ever, because the lead had been cut. My first sign of trouble would have been magic smoke escaping and perhaps the need for a fire-extinguisher.
<p>
Leaving bread crumbs for discovery is a really simple and helpful way to document your adventures.
<p>
Thank you Walter VK6BCP (SK) - it's been a pleasure to know you through your shack.
<p>
I'm Onno VK6FLAB
Listen:
Lessons Learnt
Foundations of Amateur Radio
<p>
Lessons Learnt
<p>
Learning to me is an ongoing process. For some reason that's not a universal experience. I've met people who cram for an exam, pass their test, get the certificate and hang out their shingle. The retained knowledge is spotty and vigorously defended as the final word on the topic.
<p>
It's never been like that for me. I tend to walk through life intensely curious about the how and why of a thing.
<p>
Take my recent adventures operating a new to me radio with a new to me antenna in a new to me location. It went sideways, fast, with little direct evidence of the experience to show for itself.
<p>
I did learn several things.
<p>
I expected that having switched on the radio at home, transmitting into a dummy load and receiving was enough to prove that the radio was operating normally.
<p>
The fact that I didn't hear anything and didn't know if that was because of my set-up or the radio itself was not helpful.
<p>
I expected that bringing a long-wire with a multi-tap un-un would guarantee that I'd be able to operate on any band.
<p>
The fact that I got a high SWR everywhere didn't tell me what the cause was and not having access to my testing equipment made troubleshooting much harder.
<p>
I expected to plug the radio into the car and brought battery terminal clip adaptors and a cigarette lighter plug adaptor to facilitate this.
<p>
I didn't expect to operate separate from the car, hadn't considered that the voltage might drop below acceptable and didn't know how fast that might happen. I sort of expected that the radio would have a voltage display, but so far that's eluded me. I even have an in-line Volt meter back at the shack, would have been more useful than the torrid I packed.
<p>
I expected that the length of the power leads would be sufficient to comfortably install the radio into the car and operate without having to be mindful of where to put my feet.
<p>
I didn't expect that the power lead was only just long enough to place the radio in the passenger side foot well and didn't offer any flexibility at all.
<p>
I expected that I had taken with me enough in the way of connectors and adaptors to connect various antenna options together.
<p>
I did. I managed to bring one surplus item which couldn't be connected and didn't need to be either.
<p>
I expected that my coax patch lead was sufficient to have the radio inside the car and the antenna outside the car.
<p>
It was. Just.
<p>
I expected for planning purposes that Google Maps would work the same as it does at home. Satellite and street views pretty much in sync and roads shown on the map actually existed.
<p>
It didn't. The satellite view was current, street view was 11 years old for some streets, pre-building boom, pre-cyclone, pre-historic pretty much. There were roads indicated that didn't exist, couldn't exist, had never existed and would never exist. The place I stayed at has been there for more than a decade, but Google Maps shows me surrounded by water. The local board walk has been there for over 30 years, but Google doesn't know it exists.
<p>
I expected to be able to get anything missing from my kit with little trouble from local big box stores.
<p>
In reality, the local electronics dealer is an authorised stockist of a well known brand, capable of ordering in most stuff, but a full brand store with actual stock was well over 100km away.
<p>
I expected that buying a battery locally might cause weight issues for packing luggage.
<p>
In reality, shipping batteries across the country is non-trivial and in many ways should be budgeted as a disposable item, since shipping is likely to be either not permitted, or cost as much or more than the original purchase price. It boggles the mind how these batteries actually arrive at the shop where you buy them, but no doubt that's above my pay grade.
<p>
I'm sure there's more to learn from my adventures, but I'm happy to have experienced this to add to my skill set as a radio amateur.
<p>
What learning have you been exposed to when you least expected to be?
<p>
I'm Onno VK6FLAB
Listen:
Going on an outing
Foundations of Amateur Radio
<p>
Going on an outing
<p>
After my fun and games working out how to manage power for a temporary radio set-up, away from my shack and normal infrastructure, I had the pleasure of actually going out to get on air and make some noise.
<p>
A national contest was on offer and it's always been a favourite of mine. It's simple to log, you can work as much or as little as you like and there's generally a good community spirit associated with it.
<p>
After mapping my way around the neighbourhood, I'd found a few candidate locations, nearby water, trees, parking, bit of separation from housing, all the good stuff you need when you go walkabout.
<p>
Had the opportunity to configure the car, setting up in an underground garage, nice and cool, good light, perfect start to a contesting day. Found a suitable route for the power lead from the battery to the radio, set-up the various bits, microphone, dummy load, untangled the wire antenna, all ready to go.
<p>
Got in the car an hour before the contest started and drove 5 minutes up the road to contesting location candidate number 1. Shame about the overhead power lines. On to location 2, shame about all the cars, location 3, overhead power lines, location 4, no parking signs, location 5 through 7 couldn't be found because the map and reality didn't quite agree with each other.
<p>
At that point I made the decision to go and have some lunch. Best thing I could have done. There was another location, number 8 or 28, who cares at this point, but it was 50km away, just under an hour drive. My trusty navigator and aspirant logger and I decided to bite the bullet and head on out into the great unknown.
<p>
We arrived an hour after the start of the contest. Drove up and down the shore of a local man-made lake and after dismissing several full sun locations, found a little dead end track with nice trees and plenty of shade. It's a 26°C day, so sitting in the full sun is not a pleasant thing in a dark car.
<p>
Used my rope and gifted weight - thanks Alan VK6PWD - to find a spot for the antenna wire, set-up and powered up. Tested the SWR. High, everywhere. Tested with different un-un settings, 16:1, 9:1, 4:1, high, everywhere. Found a loose connector, one I'd tested before packing and then another. Replaced them both, still high. Dummy load was fine.
<p>
Tried three different antenna layouts and decided to see if I could actually hear anything. Listened to all NCDXF beacons on all bands. Nothing. Not a sausage. At least the cattle coming past for a look-see were having a great time.
<p>
After all that, the only thing left to do was to pack up and drive home. Mind you, we did find a nice red wine on the way home, so it wasn't a complete loss.
<p>
In past years I might have been quite upset about this experience, but with experience comes acceptance that sometimes it's just not your day.
<p>
I'm furiously scribbling down all the things I've learnt from this outing. I'll leave that for another time.
<p>
I'm Onno VK6FLAB
Listen:
Planning for an outing
Foundations of Amateur Radio
<p>
Planning for an outing
<p>
Recently I had the opportunity to use a new radio whilst I was far away from my shack. It wasn't unexpected, I took the radio with me, planned for the experience and packed light with intent.
<p>
My original packing included a 10m length of coax, my analyser, some antenna weights, wire, rope, power leads, BNC adaptors, barrel connectors and a balun. Total weight came in at about 7kg. More than double the weight of the radio itself. The biggest weight came with the coax, so that stayed home. Got rid of all the "what-if" adaptors, dumped the antenna weights, dumped the balun and the analyser, added an un-un, and a multimeter and came in at just under 5kg.
<p>
The idea was to operate from the car, chuck a long-wire into a tree and make noise.
<p>
Then I got to where I was going and learnt that there were lots of SOTA peaks nearby. If you're not familiar with SOTA, it stands for Summits On The Air and it's a way of encouraging people to go out and make noise while also encouraging others to listen out for your activation of a nearby peak. As an aside, it's separate but closely related to WWFF, World Wide Flora and Fauna, since peaks are often in National Parks and who wouldn't want an excuse to activate two things in one sitting?
<p>
One of the most basic rules of SOTA is that all equipment must be operated from a portable power source (batteries, solar cells, etc). Operation is expressly forbidden using permanently installed power sources or fossil-fuel generators of any kind.
<p>
That of course means that using the battery in a car is not allowed, though I suppose I could unbolt the battery from the engine bay, but I'm pretty sure that the hire-car company would frown on that plan.
<p>
I set about attempting to find out how much power the radio actually draws at 5 Watt, and how much battery I'd need to activate a peak.
<p>
Given that my shack wasn't where I was, I couldn't just plug it into my fancy power supply and read the power draw from the display, should have done that before I left. Shoulda, Coulda, Woulda. I resorted to asking the community, but that was dependent on the kindness of strangers.
<p>
Another hitch was the battery. I came up with the brilliant plan to use one of those high-capacity jump start boxes, 18Ah or so. Picked the one I liked the best, figured out if I could ship it back to my shack on return, since it likely couldn't fly, both from a weight and a dangerous goods perspective and found a supplier locally - well 108km away - and then, me being me, I downloaded the user manual, and learnt that what I wanted to do, power my radio, was expressly, strongly, not recommended, fear of explosion and the like.
<p>
Planning foiled.
<p>
I still wanted to operate, contest to be attempted, SOTA be damned. How could I operate and not fear that I'd be draining the car battery?
<p>
A cigarette lighter mounted Volt meter!
<p>
So, now I can connect the radio directly to the battery in the car and check the voltage whilst I'm operating.
<p>
Now all I need is a parking spot with a nearby tree or gazebo and no noisy neighbours or overhead power lines.
<p>
I'll let you know how I go.
<p>
I'm Onno VK6FLAB
Listen:
Boating adventures
Foundations of Amateur Radio
<p>
Boating adventures
<p>
The other day I was on a boat. That's right, me, on a floating thing, on the water, the ocean actually, steering and everything. I should confess that when I was younger I spent most weekends sailing as a sea scout in Holland.
<p>
Managed to become a bootsen, that's the bunny in charge of a boat. Sea scouts, zee verkenners, was also my very first introduction to amateur radio through JOTA, Jamboree On The Air, where scouts across the globe come together, though it didn't make quite as much impression as breaking the middle finger on my right hand an hour later, but that's a story for another day.
<p>
So, me, on a motorboat, a tiny one, but still.
<p>
You may be wondering where this is going, trust me, it's relevant.
<p>
In preparation for my boating adventure I pulled out my trusty hand held radio, a waterproof Yaesu VX-7R. If you're not familiar with it, it's a tiny radio, capable of tuning between 500 kHz and 1 GHz, not quite DC to Daylight, but impressive nonetheless. I have it programmed for all registered Australian repeaters. One state per group in case you're planning to program yours.
<p>
One of the in-built options is to select Marine Channels. They're numbered from 0 to 281. I've looked in the past and in Australia the channel numbers don't follow any logic as simple as that. Numbering is all over the place, 84 channels as far as I can tell, I had to count them, the highest channel number is 2086 and there's channels with names like AIS 1 and AIS 2 rather than numbers.
<p>
If you're a yachtie, you're laughing your head off right now, but I'm making a point about Amateur Radio. We don't do channels here, well mostly we don't, unless we picked up an ancient radio cheap from somewhere and re-purposed it for Amateur Radio, but to coin another sailing term, by and large, we do frequencies.
<p>
So, here's the thing. My radio is perfectly able to transmit on marine frequencies and being a responsible person I thought it would be smart to bring my radio, just in case. I will confess that I didn't. After discovering that the marine documentation was all about channels, and decoding frequencies was beyond a quick look-up, I thought that it would be prudent to leave my radio at home. I had a mobile phone with me, was staying near to the marina and the boat owner actually supplied a radio.
<p>
So here I am, a semi-experienced radio amateur, completely clueless about marine radio. While I was figuring out how to tell you about this, I managed to find the government website which referred to a training website which referred to a user guide that actually had a list of channels and frequencies side-by-side. You'll be pleased to learn that channel 16 on my radio, the emergency marine channel is on the same frequency as the official channel 16 in Australia.
<p>
My point is this. We have a common interest in communicating. In the case of an emergency it would be useful to know what marine channels relate to what frequencies and how we as radio amateurs can help if required. It also means that we as radio amateurs are not the all knowing beings we believe ourselves to be. Of course we already knew that, so we keep learning.
<p>
I know I'm going to learn how marine radio channels work. I'll probably have a look-see at other channel spectrum users and see how they relate, so I can know how their system works in case I ever need to.
<p>
I'm Onno VK6FLAB
Listen:
Gate-keeping, special people and bullies.
Foundations of Amateur Radio
<p>
Gate-keeping, special people and bullies.
<p>
One of the recurring topics in my experience of amateur radio is that associated with people who use the hobby as an excuse to sow discontent. That comes in many forms, at the extreme end it's harassment, but it also comes in the form of gatekeepers and nay-sayers.
<p>
It's important to realise that while this behaviour is not limited to amateur radio, we seem to have more than our fair share of the negative element.
<p>
When you come into this community, all bright-eyed, excited, willing to learn, you might be astonished just how negative some community members can be. You might pick up a special friend who follows you around, either on-air, or on-line, rarely in real life, who makes it their mission to make your life a misery.
<p>
This behaviour manifests itself with statements about the unsuitability of your license, your equipment, your gender, your knowledge, your examination process, your chosen frequency, your selected mode, anything that's not to the liking of whomever challenged your existence.
<p>
This kind of behaviour is known as gate-keeping and in amateur radio it's rife. People with a chip on their shoulder, the size of Montana, with nothing better to do than berate new amateurs, tell them off, preferably as a means to explain to them why they should leave the hobby or are not worthy of being considered an amateur.
<p>
In addition to these delightful utterances, I regularly see sexist, racist and other content shared among our community that would not be condoned in the workplace, let alone in the family home.
<p>
Why do we as a community tolerate this extreme behaviour when in the rest of our lives this is strongly discouraged and can lead to severe consequences such as dismissal and legal proceedings?
<p>
In civil discourse we treat each other with respect and that should be there regardless of the environment, be it professional, the home, or in this case a hobby.
<p>
It's been said that for some people in amateur radio, their biggest life achievement was the gaining of their amateur license. The acronym FIGJAM comes to mind to describe some of those entitlement rich individuals.
<p>
So what do you do when you are confronted with a repeater troll, or told that you don't measure up because you don't know Morse, or some other denigrating statement?
<p>
Previously I would have advocated that you ignore it and move on. Often times you've done nothing wrong and there's nothing to be gained from arguing the point.
<p>
There's only one problem with that. There is no cost to the bully, let's face it, we're talking about bullies, minor or major, still a bully.
<p>
No cost means no disincentive, which means that the behaviour continues until the bully gets bored. Only problem is that you'll need to weather the storm while that happens. Not good for you, your mental health or the mental health of the people around you. That's not a good balance.
<p>
As a community it's our job, that is, my job and your job to call out this behaviour and to expose it for what it is, abhorrent, elitist, sexist, racist, gate-keeping. I've been told that this isn't real and that I should leave this alone and to that I say: No. This is my hobby too and I get to have a say about what kind of hobby community I'd like to be part of.
<p>
So, instead I think we as a community need to do something more active. I think we, that is, you and I, need to call out a bully when we encounter one. It does't have to be confrontational, however satisfying that might be, but it needs to draw a line in the sand.
<p>
For example, you might say something like this:
<p>
Thank you for your comment. I don't believe that it's in the spirit of amateur radio. Please stop.
<p>
It's not going to end the behaviour of the bully, but it does achieve some other things. If this is on-line, it will flag for future readers that something is amiss and on-air it will highlight to fellow frequency users that you're not OK with what's going on.
<p>
It does some other things as well. For you it will give you a sense of ownership of what's going on around you, rather than being pushed into the role of victim. It will also give the bully a statement that's neutral whilst indicating that their behaviour is unacceptable.
<p>
I think that the only way out of the keyboard warrior and repeater-troll hell we find ourselves in is to do something different, to make noise, to shine a light and to discourage bad behaviour.
<p>
One thing I can say from personal observation is that what we as a community have done to date isn't working. It's getting worse. We're alienating good people who want to make a contribution and we're doing nothing to discourage those who are sure of their position and are unapologetic about how they express that superiority.
<p>
Step up. Call it out.
<p>
Thank you for your comment. I don't believe that it's in the spirit of amateur radio. Please stop.
<p>
I'm Onno VK6FLAB
Listen:
New Entrants are Everywhere
Foundations of Amateur Radio
<p>
New Entrants are Everywhere
<p>
The hobby of amateur radio has been around for a long time. It was here before I was born and it will be here after I become a silent key. The same is true for you. While there is a recurring discussion about the death of the hobby, the reality is that our community changes continually. People come and go all the time. Reasons for change are as varied as the number of people you care to look at, from interest through to family, from money through to time, from boredom through to excitement, from life through to death.
<p>
As our community fluctuates, our skill level varies. We see new people come into the hobby, bright-eyed and bushy-tailed, ready for a new adventure, at the same time we have people who are experienced, or jaded, or both, participating in the community and finding themselves answering the same questions over and over again.
<p>
What radio should I get? Is this radio better? How do I do HF? How do I get my license? Where is everyone? How do you participate in a net? Which antenna should I buy? What is a QSO or a QTH? How come this and why that? At some point I was that person and I have no doubt that at some point you were, or are that person.
<p>
The challenge in maintaining a semblance of community coherence is to balance the needs for new and aspiring amateurs with the expectations of those already in the community. How do you answer the same questions while staying fresh and encouraging, when all you really want to do is ignore the noise and get on with the hobby?
<p>
The answer is simple.
<p>
You need to recognise that the change in the hobby is fundamental. New people coming in, new technologies, new hardware, new modes, new rules, new customs, all of it is in flux all the time. It shouldn't be seen as a threat, but as par for the course, something that is part of our community and part of why and how we exist.
<p>
To draw an analogy with something else, cooking. We've been doing that for a while, some suggest as far back as 2 million years ago. Every day new people learn to cook, new people invent or reinvent recipes, cooking classes abound, television shows with competitive cooking, new ingredients, new tools, new techniques and relearned old methods, there's celebrity chefs, awards and the more you look at cooking, the more you understand how it changes and continues to change. In many ways cooking and amateur radio are the same.
<p>
The idea of teaching your child, or a friend, or a person on social media how to cook something is accepted as how it is and how cooking evolves.
<p>
In amateur radio we can do the same.
<p>
It's easy to dismiss silly questions, or to give snide answers, or to ignore new arrivals, but that's not something that grows our community, strengthens it, or broadens it.
<p>
Of course, how much you participate in this is the real yardstick of how much of an amateur you really are. Said in another way, if an amateur calls CQ into a dummy load, does anyone care?
<p>
One of the challenges as a new entrant into the community is to figure out where to go and how to learn more. It's never been easier than it is today, even if you think that it's hard. In a bygone era you had to go to a library, or to find another amateur, or go to a club to even know that our hobby existed, these days the access to our community is within reach for any person on the planet.
<p>
We have endless resources, in the form of web-sites, books, both electronic and paper, clubs, virtual and physical, social media, podcasts and articles such as this, video channels, and an endlessly growing and evolving community that cannot help but document its adventures and exploits.
<p>
Amateur radio today is as close as the nearest search engine and as far as you want to take it.
<p>
Never be afraid of asking a question and consider it a right of passage if a grumpy bugger tells you off for asking a stupid one.
<p>
The worst question is the one you never asked.
<p>
I'm Onno VK6FLAB
Listen:
What's in a Watt?
Foundations of Amateur Radio
<p>
What's in a Watt?
<p>
We need more power. I'm giving her all she's got, Captain! She cannae take anymore.
<p>
I'm sure your Scottish ancestors are rolling in their graves right now, but in our community of radio amateurs we have a tendency to advocate the use of more power. More power fixes all problems and hides all sins.
<p>
Another way to look at that is to think of the station with more power as an aligator, all mouth, no ears.
<p>
Before you dismiss this as another avocacy for QRP or low power, let me point out that more power creates more interference, more potential for harm, more electricity consumption, more wear and tear and more cost.
<p>
Previously I've spoken extensively about QRP communications, making contact with 5 Watt or less, but let's have a look at how much less.
<p>
I've shared with you that I managed to contact a station on the other side of the planet with only 5 Watts, Perth to Cuba and for me that was proof positive that all this was possible, even feasable.
<p>
We're doing much better than that.
<p>
One measurement is to calculate how many kilometers per Watt you achieved. My example of 5 Watt between Perth and Cuba is the equivalent of 3592 km per Watt. The maximum distance to the opposite side of our globe is about 20,000 km and my contact did nearly 18,000 km.
<p>
If you think that's amazing, I should warn you, my contact was special, for me, but as low power contacts go, it's not that amazing.
<p>
The first solid state radio contact made across the Atlantic ocean managed over 76,000 km per Watt. That was on 18 September 1956. You'll find the radio on display at the ARRL Laboratory, together with the bug and station log showing the contact between Chelmsford, Massachusetts and Copenhagen, Denmark between Gus W1OGU and Bo OZ7BO, on a radio made of two germanium transistors and built by Gus W1OGU, Al W1OSF and Dick W1UBC, who built the diminutive gadget on a lark to see if they could Work All Continents with it.
<p>
If you can copy the 40 microwatt CW beacon run by the North American QRP CW Club, you too can join in the fun. The current record stands at just under 22 million km per Watt when Bill W4ZV managed to copy the code word OMAHA from the N2XE beacon from New London, North Carolina.
<p>
Just to be clear, we're talking about a signal that travelled the equivalent of 22 million km using 1 Watt of power.
<p>
If you think that was amazing, Pioneer 10 managed to achieve 1.3 billion, that's 1.3 thousand million km per Watt in 2003. Mind you, that record was achieved with a slightly bulky antenna, the Deep Space Network.
<p>
Are you ready for more?
<p>
The current record stands at just under double the Pioneer 10 record, just under 2.6 billion km per Watt. That was achieved by Dick KL7YU and Bill W7BVV who made contacts between Alaska and Oregon in December 1969 and January 1970. A distance of 2655 km using one micro Watt.
<p>
Yes, you can throw a Kilowatt at the problem, or you can take your time, do some work and have some fun with low power.
<p>
You can call it QRP, or you can call it just enough to get the job done.
<p>
I'm Onno VK6FLAB
Listen:
It broke and now what?
Foundations of Amateur Radio
<p>
It broke and now what?
<p>
Imagine you're a new amateur. You've woken up in the middle of the night because insomnia seems like a good way to use amateur radio as an excuse to get on air and make some noise. You turn on the radio, key up the transmitter and the next thing you know it's dark. The breaker that powers your radio popped and there's no more glow coming from the hardware that's warming up your shack.
<p>
You get up, reset the breaker, tighten up your dressing gown and switch on your gear. You sit down and key up. Pop, darkness.
<p>
What do you do next?
<p>
The first thing to realise is that there is something wrong. That might sound obvious, the radio just tripped the breaker and it went off, but sometimes it's not that obvious, sometimes there's something wrong, but it's not nearly as clear as light and dark. For example, you might key up and the SWR goes high. You might not even notice if your radio is set to monitor the power output, or the automatic gain control that indicates how well your audio is going out.
<p>
The point is that noticing that something is wrong is a matter of paying attention. Just sitting there all dumb and happy, mashing the microphone is going to cost money or cost something else one day when you stop paying attention.
<p>
So, finding out what's wrong starts with noticing that something is amiss.
<p>
If you've been clued in that something is broken, and you're not standing next to your radio with a fire extinguisher, or tears running down your cheeks because you just blew up your new radio, you can move onto the next part of this little adventure.
<p>
One thing to note is that it's really easy to make it worse at this point. Making it worse arrives in all manner of different ways, pain, either physical, RF burns, smoke, sparks, or mental like the emptying of your wallet when it goes pear-shape.
<p>
The art of troubleshooting is the process of attempting to learn what's going on. Some people know instinctively how to do this, others just wiggle stuff, unplug stuff and hope for the best. Hoping for the best is not the best plan.
<p>
One of the most basic aspects of troubleshooting, of trying to figure out what's happened, is to document what you find. Write it down. I know you're going to skip this, but it's going to bite you and then you'll be sorry and I'll be here telling you that I told you so. So write it down. Be meticulous. In case you're wondering, you're doing this for your own benefit, not my sense of curiosity. If you measure a value now and it's 7 Ohm and you change something and then you measure again and it's 23 Ohm, if you didn't write it down, you'll never know. Especially if the two measurements are a week apart.
<p>
Next basic concept is to change as little as possible, preferably one thing at a time. That's easy for me to say while your reptilian hind-brain is currently attempting to decide between whom to murder first and how fast to run. There is a tendency during panic to wildly wave your hands about and fiddle with lots of stuff. The urge to do that is strong. Resist that urge with all that you have. Again, you're going to ignore that and I'm going to stifle my I told you so chant, but less is more. This is important. If you change two things, you've just doubled the possible causes. If you change three, there are now six different causes and if you change four things, we're up to 24 different versions of the problem. Keep it simple.
<p>
Third concept is to test things. The smaller the test, the better. For example, you're connected to the right antenna, right? The power supply is giving out the right voltage, right? The squelch is open, right? The microphone is plugged in, right? Test each of those, one at a time. The more you troubleshoot, the more this list will come naturally. Right now you're probably cursing me for not supplying you with a ready-made list. That's because my shack is nothing like yours, not even a little bit. Also, your shack keeps changing. Besides we're learning the skill of troubleshooting and I already know how to do that. Mind you, truth be told, I've been known to make mistakes too, so there's that.
<p>
Forth concept is about testing gear. There is a tendency within our community to buy gadgets. The more the better, a volt meter, an ohm meter, an ammeter, an SWR meter, an oscilloscope, a VNA, a what-ever. The more toys the better. While toys, uh tools, help, they're not the answer to every question. You have a more fundamental issue to deal with. Garbage in equals garbage out. If you measure ohms, but needed volts, there's no helping you. So, instead of focussing on what new tool to acquire, focus on what measurement you need to make to prove that something works, or doesn't.
<p>
The process of troubleshooting doesn't come naturally to everyone. I know, I've seen some very panicked people break some very expensive hardware, seen full-bright scholars make bonehead mistakes and heard stories of physicists narrowly avoiding electrocution, so don't be shy when you say that you're not sure how to really do troubleshooting.
<p>
You can learn. We all did, me included.
<p>
I'm Onno VK6FLAB
Listen:
What's in a word?
Foundations of Amateur Radio
<p>
What's in a word?
<p>
When you join a new community you learn very quickly that each community has its own language. A word in one community has a different or extra meaning in another. For example, the word "Snowflake" in one community might refer to a phenomenon related to water and freezing, in another community it refers to a person who is sensitive, easily hurt and offended. If you mix the two meanings all manner of misunderstanding ensues.
<p>
In amateur radio, one of those words is the word gain.
<p>
This word is used in many different aspects of our hobby, but today I'm going to focus on one specific use of it, in relation to antennas, antenna gain.
<p>
This mythical property of an antenna is often used as a way to distinguish two different antennas and in advertising terms, bigger is better, more gain, more better. I'll skip over the marketing shenanigans related to artificially making the number larger by comparing apples and pears, or dBi and dBd and move on to how gain comes about.
<p>
Let's look at something completely different. A light bulb. One of those tiny ones you find in a torch, or on the front of your bike or even one in your car. In essence we have a gadget that emits energy in the form of light and heat when electricity is applied. The specifics aren't important, but let's just say we're going to ignore more voltage and more amps for the moment.
<p>
If you have a bare light bulb, light and heat radiates in almost all directions. You can't see any light where the fitting is, but everywhere else is a pretty uniform pattern. For the moment, let's ignore the fitting.
<p>
If you were to get a piece of black cardboard and drill a hole and put the light through it, you've essentially removed half of the light. Below the cardboard there is no light. Above the cardboard is the same amount of light as before. Half the light is being stopped by the cardboard and it's essentially lost - technically it's getting absorbed and the cardboard is getting a little warmer, but let's not confuse the issue for the moment.
<p>
If you were to make the cardboard reflective, say some foil, white, a mirror, whatever, the light that was hitting the cardboard would be reflected away from the cardboard and you'd experience that as the light getting brighter. Notice though, it's still dark below the cardboard.
<p>
In essence you've just increased the gain of your light bulb and it didn't cost you any more electricity to make that happen.
<p>
Antennas work in much the same way. There are a few more wrinkles. A light bulb is working with light and heat frequencies, wavelengths are between 100 micrometers and 100 nanometres, where the antennas we use in amateur radio typically look at 100 meter to 23 centimetre, so the material aspects of our mirror equivalent are different, but have a similar idea.
<p>
One thing that's fundamentally different between a light bulb and an antenna in our hobby is that a light bulb is generally only transmitting, where we tend to both transmit and receive with an antenna.
<p>
Remember when I skipped over the bit of the light bulb below the cardboard being dark? That's the antenna equivalent to not hearing something, which means that you're better able to hear the signal in the direction you're pointing. The same is true for the bit about the light bulb fitting and no light below it.
<p>
In antenna terms, this phenomenon relates to the front-to-back ratio. Imagine turning your antenna 180 degrees. Pointing one way the signal is of this strength, pointing the other way it's that strength. Divide the two. If they're the same, the front-to-back ratio is 1, otherwise they express the directivity of the antenna. Another number you can use to market your antenna to an unsuspecting amateur.
<p>
So far we've only looked at using a single reflector for our light bulb, but if you were to use a torch, you'd get even more directivity and more gain. The same amount of energy, pointing at a smaller area. The ultimate expression of this is a laser beam, which is essentially a single focussed beam of light with no light anywhere other than where it's pointing.
<p>
Antennas do the same thing, using different methods, but the most common one is to add more bits of metal to focus the radio energy.
<p>
A light bulb emits energy in all directions and an antenna does too. Even if you were to make an antenna made of elements, all aligned in the same direction, the pattern is still mostly round, that is, it's like a cone of radio, regardless of the shape of the antenna.
<p>
Yes, there are ways of making antennas that don't make round cones, but that's a conversation for another day, but think about this, what would happen if you were to squash an antenna pattern and then focus it?
<p>
I'm Onno VK6FLAB
Listen:
How far can I talk on radio?
Foundations of Amateur Radio
<p>
How far can I talk on radio?
<p>
A question that regularly hits the enquiring minds of people who are not (yet) radio amateurs is one about distance. For both amateurs and those who are not ye) inducted into our community the concept of distance speaks in ways that other parts of our hobby don't. It's a simple concept, between these two points, how far can you talk?
<p>
The interesting thing to me about this phenomenon is that distance isn't a metric that we as amateurs use for anything other than calculating repeater coverage and then only for frequencies that are line-of-sight. If you're not an amateur then this might be unexpected or even illogical.
<p>
Let me give you two questions:
<p>
How far can you talk in amateur radio? - and - How far does light shine?
<p>
If you're an amateur you'll know that those two questions are pretty similar, if not identical for certain frequencies, but if you're not, then these two questions appear completely unrelated to each other.
<p>
Let me start with something that you might not realise. If you tune to a local AM radio station, let's say ABC 720 in Perth. It's located in the AM broadcast band and the number of the station, 720, is the frequency at which it's transmitting. 720 kHz, or 720 thousand Hz. If you had a radio capable, you could turn the dial to the right, and after passing 810 Radio National, eventually, if you kept turning to the right, you'd find ABC Classic FM at 97.7fm in the FM broadcast band. The station indicator, 97.7 is again the frequency, 97.7 MHz, or 97.7 million Hz. So, 720 and 97.7 are both on the same dial, just at different ends.
<p>
Now if your radio was capable, you'd be able to keep winding it to the right, and after passing by Wi-Fi, at 2.4 GHz, or 2.4 billion Hz, you'd eventually come across light. Green light for example is about 560 THz, or 560 trillion Hz. You could keep going and end up with even more exotic stuff, like X-rays and Gamma-rays, in the exahertz range, a 1 with 18 zeros, but you get the point. Radio and light are the same thing. If fact, there are experiments around that are using light for Wi-Fi communications.
<p>
So, How far does light shine is the same thing as How far can you talk in amateur radio?
<p>
Before you start complaining about when it's different, let me point out that the only difference between these two is the frequencies at which we're comparing, with the characteristics that come with that. I'll get to that in a moment.
<p>
Look at light.
<p>
If you have a light bulb that's bright enough, you can see it in full daylight. If it's dark outside then you'll need less of a light bulb to see it. If it's raining, or if there is smoke in the air, you'll need more. If there's a wall between you and the bulb, you'd need a pretty bright light to shine through the wall, but you already know this. Covering up a torch with your palm shows the bones in your hand. Light gets through different parts of your hand in different ways.
<p>
Another thing you've seen is when you put a straw into a glass and it looks like it's broken. That too is related to how light travels through different materials. You may even have been underwater in a pool and looked up to see a reflection. That too is a phenomenon familiar in amateur radio.
<p>
Something that you might not realise is that something like an X-ray is identical to shining a light of a torch through your palm. Only X-ray's are used for diagnostic purposes, we shine an X-ray light at your body and some gets through and some doesn't. We take a photo of that and use it to figure out what's under your skin.
<p>
Back to radio.
<p>
The same phenomena happen in radio. Buildings are good at stopping certain radio frequencies, in much the same way as they block light, but other frequencies barely get noticed, they shine right through. Similarly, the ionosphere around the earth can act as a reflection like the surface of a swimming pool for some frequencies, but not for other frequencies. Interestingly this changes throughout the day, depending on the sun and a whole range of other factors which I'm not getting into today.
<p>
Finally, just like with light, you can turn up the brightness for different effects, you'll get further, but only if the conditions allow for it.
<p>
To answer the original question about how far you can talk on amateur radio becomes much harder and now you know why.
<p>
I'm Onno VK6FLAB
Listen:
What's allowed on our bands?
Foundations of Amateur Radio
<p>
Recently there was a discussion on social media about the legality of various types of transmissions. Before I get into the specifics, it's worth looking at some of the rules around this. I will point out that this isn't exhaustive, but it gives you an idea of what I'm talking about.
<p>
In Australia, the rules about this are encapsulated in the Radiocommunications Licence Conditions Determination, referred to as the LCD. It essentially says that you must not operate an amateur station to transmit signals that are encoded for the purpose of obscuring the meaning of the signals, except for amateur satellite and repeater command and control purposes or emergency service operation and training.
<p>
In the United States, the rules are covered under the FCC rules, Part 97 Amateur Radio Service. It says that you may transmit using a digital code who's technical characteristics have been documented publicly. It goes on to prevent such transmissions for anyone communicating with a country that doesn't have an agreement with the United States. It also states that using unspecified digital codes must not be transmitted for the purpose of obscuring the meaning of any communication and if it's deemed necessary, you must maintain a record, convertible to the original information, of all digital communications transmitted.
<p>
In the United Kingdom, the amateur terms say that the licensee may use codes and abbreviations for communications as long as they do not obscure or confuse the meaning of the message and messages shall not be encrypted for the purpose of rendering the message unintelligible to other radio spectrum users, except for during emergencies or if used by various emergency or government departments.
<p>
Just by looking at three different sets of rules we can already tell that law makers across the globe have different ideas of what's allowed and what isn't. I will point out that the rules in the United States are much more prescriptive than those in Australia or the United Kingdom. I'll leave it to lawyers to determine which of the rules is more effective and what their actual effect is on our global amateur community.
<p>
Let's get back to the original question. What's allowed?
<p>
The purpose of obscuring the meaning of the message is essentially not allowed. What happens if that's a beneficial side-effect? Is that allowed?
<p>
For example, let's imagine that I have a new mode that is more efficient than any other mode in getting information between point A and point B. It does this by transmitting a single number, which is simply sent and received, it could even be done with Morse code.
<p>
Station A knows what the message means and Station B also knows what it means. How they come to a common understanding of the message is something I'll leave to your imagination, but is this kind of transmission in violation of the idea of obscuring the meaning of the message, if all we're doing is making communications faster?
<p>
Let's say that we have a public web-site that links those numbers we've exchanged to a more meaningful message. Let's say that Station A uploads an image to this website, and then sends an ID number of that image to Station B, which then goes to the same website and looks up that ID and sees the image. Bingo, transmission complete. Message exchanged. It's all public, there's no intent to obscure the meaning, everyone happy. In case you're wondering, I've just described how Hybrid EasyPal works.
<p>
What happens if I require a password to access the website to see which file was intended for me? Have I just obscured the meaning of the message? Note that I'm talking about two stations exchanging a unique identifier of some sort, that both stations have agreed on, so they can communicate via a password protected website using amateur radio.
<p>
That appears to be in violation of the amateur radio rules for all three countries.
<p>
It gets better.
<p>
What if I build a gadget that makes squeaky noises and knows how to receive them? Station A plugs their microphone into the gadget and talks into it. The gadget makes squeaky noises and those are transmitted. Station B has the same gadget, which understands squeaky noises and makes it into perfect audio. The purpose is to get information between the two stations, no intent to obscure the message, right?
<p>
What if I only make two of these gadgets?
<p>
The purpose isn't to obscure, but the outcome is that the messages are actually obscured. At this point we get lawyers involved who argue both sides. Your honour, I wasn't trying to hide my communications, I was just making them more efficient.
<p>
Clearly this isn't what our hobby is about. It's about exchanging information, un-obscured information, between stations that want to talk to each other.
<p>
If the intent is to make apples, but the outcome is that you're making pears, you're making pears.
<p>
I'm Onno VK6FLAB
Listen:
Your Software Defined Radio around the home
Foundations of Amateur Radio
<p>
What would you do if you found that at random times your garage door opener didn't work, or the Wi-Fi network dropped out, or you couldn't switch off a light with an RF controller?
<p>
That's the position I found myself in and the times at which this was happening were madly unpredictable. One moment everything would work fine and the next all things radio would just stop.
<p>
As a radio amateur you're likely nodding your head and thinking, radio interference, there's some direction finding in your future. Sure enough, that's the case, but before that, I needed to know if the interference was random, if it had a particular pattern and how widespread it was, since it seemed to impact multiple different devices using different parts of the radio spectrum.
<p>
Initially I focussed on getting a recording of it. I turned on my radio, tuned it to a 2m frequency and recorded the noise. Only one problem. There was no noise. All I could see was an extreme signal strength, but it wasn't showing up as noise.
<p>
I enrolled the help of my RTL dongle and recorded some raw data, essentially capturing a 3 MHz slice of noise centred around 147 MHz. All that revealed was that there was noise. I already knew that.
<p>
At that point I decided that a bigger hammer was needed. Something you can do if you have a $5 RTL-SDR dongle and some free software, in my case I used a tool called rtl_power and a visualisation tool called gnuplot.
<p>
rtl_power is a nifty piece of software. It takes measurements and averages out the power level across the measurement range. To make it work, you specify a starting frequency, a stopping frequency, how big a step to use to average, how often you want to measure and for how long.
<p>
For my little investigation I started with measuring between 0 and 1.7 GHz, at 1 MHz intervals, every 2 minutes for 10 days. That creates a big CSV file that you can process with gnuplot into a picture that tells a thousand lies.
<p>
Seriously, it showed me that the interference was very wide, 0 to 300 MHz, it occurred every 20 or so hours, lasted up to six hour at a time. There were other things happening as well, similar patterns, but across an even larger frequency range, from 0 to 600 MHz, but in shorter duration and of lesser strength.
<p>
Based on the times alone, I can immediately, almost certainly, eliminate any source under my control.
<p>
Based on the timings I can also determine that the noise is likely not created by an automatic process, given that they vary in duration and the way they're clustered around specific times.
<p>
The variation of the interference allows me to determine that there are at least three separate types of noise, each with specific characteristics and times, sometimes overlapping.
<p>
It's too early to tell if this pattern will continue. One possible next step is to set up the same measurement tool and powering it from a battery. Once I've got that working, I expect to turn off the house power during an interference session and determine if the noise is coming from my house, or if it's an external source, which seems likely.
<p>
Once I've determined if it's in house or not, I can start either eliminating gadgets by switching off specific power circuits, or I can start direction finding and locating a nearby source of pain.
<p>
At that point I can decide what to do next. That said, at the moment it looks like several televisions around me are creating an RF noise storm of epic proportions.
<p>
I've documented all of how I did this and you can find it and the scripts I created on the web at vk6flab.com.
<p>
One thing that has happened since I started documenting my efforts is the idea that we could collectively as a community make measurements like this and document the state of our RF space and how it changes over time. I plan to update my code to incorporate this idea, perhaps log in 24 hour blocks and generate a chart over that time, perhaps make it into a video.
<p>
One challenge ahead of us would be to come up with a universal way to calibrate our various dongles, so we all report the same signal level in the same way. One thought is to use the sun as a global calibration, but I'm not yet sure how that might be implemented.
<p>
One thing's for sure. If you've ever wondered what use can a $5 RTL dongle possibly be, this is one thing that you just cannot do with a traditional radio. That's not to say there's a place for both in the world, just different tools for different problems.
<p>
I'm Onno VK6FLAB
Listen:
The Software Defined Radio vs. Traditional Radio choice
Foundations of Amateur Radio
<p>
For some time I've been explaining how some of the internal workings of a Software Defined Radio operate with a view to getting into the nitty gritty of the why and the how. This exploration is happening within the context of a world where there are countless choices for selecting a radio to match your budget. Increasingly that selection process starts with a simple question: Should I purchase a Software Defined Radio or a traditional radio?
<p>
This is not a new question, previously it may have been: Should I select a radio with transistors or one with valves? Presumably the same happened when your ancestors faced a choice to buy a new car or update their horse and carriage. Of course I'm being flippant, but the point stands, as things evolve, choices change. Today we don't know what comes after the Software Defined Radio that we currently know, but it's likely to force the same selection on future generations of radio amateurs.
<p>
So, if you're in the market for a new radio, what things should you consider in your selection?
<p>
SDR is becoming pervasive, that is, the more you look, the more you'll find. Much like transistors overtook valves, not because they're better, but because there's a smaller component count and related price advantage.
<p>
SDR come in all forms, from nondescript black boxes to a traditional radio form factor and everything in-between.
<p>
If you choose a black box model SDR, there are tools around that allow you to use external controllers to provide knobs and buttons. These external controllers might be a fully-fledged radio head, or it might be using an external USB connected knob to change the frequency, or you might integrate your solution with a DJ Console, a big panel with lots of knobs, sliders and dials, repurposed as a user interface for your radio.
<p>
The software behind most SDR platforms appears to continuously be in a state of rapid development. This means that every update potentially gives you more functionality. Of course the opposite is also true, things break, get taken away, get redeveloped, in ways that may be unexpected or unwanted.
<p>
In my opinion, there's an awful lot of crap software around, attempting to use a computer screen to emulate a physical environment, forcing you to use a mouse to turn a knob, or slide a slider. It's getting better, but so far I've not seen a single solution that does this all well. That's not to say that there aren't any innovative things happening either. For example, something I've mentionned in the past, is the user interface for the diversity receive function inside PowerSDR. You set the phase angle and the strength by pulling on a line inside a circle.
<p>
There's plenty of open source software around, and functionally it's pretty good. Fortunately Windows is not your only option, Mac OS and Linux provide many opportunities.
<p>
Traditional radios have not finished, nor are they likely to go the way of the Dodo anytime soon, but while people are getting excited, you can pick up bargains from those migrating away from traditional radio to SDR.
<p>
If your selection is based on using a computer or not, there's things to use your computer for with a traditional radio, numerous and growing digital modes and other cool stuff to get your teeth into.
<p>
I should mention that there are radios about that are both traditional and SDR, so you can have the best (or worst) of both.
<p>
My recommendation is to set a budget and see what that buys you. Regardless of what you end up with, your requirements will evolve.
<p>
I'm Onno VK6FLAB
Listen:
The Regulator
Foundations of Amateur Radio
<p>
From time to time our hobby changes. While the idea that we're all a bunch of old men playing with spark gap transmitters, or using strange noises to the annoyance of others, the reality of amateur radio is markedly different from that stereotype.
<p>
The changes we experience come from many different sources. As amateurs we're always trying something new, inventing things and building stuff. That type of change is integral to the hobby and in many ways it's why our community exists in the first place.
<p>
Other changes are external. A new product arrives into the marketplace and we gleefully take possession of a new gadget. That in turn creates other changes which are incorporated into our day to day life as amateurs.
<p>
A more structured change happens when the regulator makes a proposal, instigates a new rule, enforces an old rule or does something else that affects us.
<p>
In the time I've been an amateur, I've seen changes happen that originate from the regulator that both benefit and impede our activities. Things like the introduction of new bands, the trial of high power, but also the removal of frequencies, the restriction on modes and across the globe this happens in every single jurisdiction.
<p>
For example, in Sweden the regulator proposed and then implemented a reduction in transmitter power, from 1 kW down to 200 Watt. I'm sure it made lots of noise in Sweden, but here in Australia there was hardly a squeak.
<p>
In France proposals have been drafted to reallocate the 2m band to the Aeronautical Mobile Service, to be discussed as an agenda item at WRT 2023. The 2m band is a band that is widely used, often as the first band for most amateurs, a band that offers local communication, hosts local discussion nets, has many options of affordable equipment, uses small antennas commonly installed on vehicles.
<p>
In Australia the regulator is looking at removing access to the 3.6 GHz band for specific areas and defining more precise access restrictions, removing emission mode and bandwidth restrictions and removing specific Foundation restrictions, such as the ability to build radios, connect radios to the Internet and use digital modes.
<p>
The Australian regulator is also of the opinion that any station should be able to use 400 Watts, regardless of the license level, since it's unlikely to increase interference. Interestingly, the local representative bodies are at odds with this, since they appear to believe that we need multiple levels of licence, even though I've never actually heard a coherent argument to support that.
<p>
There's more, but let's move on. What strikes me is that the benefits are celebrated and the impediments are bemoaned with hardly any thought expressed on how these changes happened and what brought them about. There are representations made by representative bodies, but most of that is at arms-length.
<p>
We're a tiny community in the scheme of things, we always have been, but we have access to one of the richest resources available and we have a regulator who is required to consider our existence when new rules are made and old rules retired.
<p>
In discussion with other amateurs I hear time and time again that making a submission is hard, it's a waste of time and takes too long. For me that makes no sense. The notion that our tiny community has no impact is not credible in the face of the evidence, so why is it that the idea of making submissions to the regulator is such a waste of time and so difficult?
<p>
Why is it that we give up before we even start? What is it in our DNA that leaves these submissions to others and what is it that makes us think we're unworthy or unable or unheard of if we never even try.
<p>
A submission doesn't have to be a book, it doesn't need to have more than one page. You can write a letter to your regulator that says: Hey, I'm an amateur, I'm affected by your proposal and I think the following.
<p>
My point is this. If amateur radio is important to you, if it gives you joy, if it teaches you stuff, if it gives you a community, if it justifies buying gadgets, then why don't you express that to the regulator when they announce a request for consultation?
<p>
What are you waiting for? Share your opinion, make your voice count, you can be part of the change.
<p>
I'm Onno VK6FLAB
Listen:
From Milk to Direct Conversion in a Software Defined Radio
Foundations of Amateur Radio
<p>
It seems my analogy with milk glasses hit a nerve when I explained some of the inner workings of a simple Analogue to Digital Converter, also known as an A/D Converter or ADC as part of my exploration into Software Defined Radio. Thank you for your comments, suggestions and corrections.
<p>
I did make an error when I said, grab eight of them and you'll have a byte, I'll get into that. Thank you for pointing it out.
<p>
With my milk glass analogy, if you missed it, without naming it, I drew a picture explaining how a flash or direct-conversion ADC works. Briefly, I said that if you were to pour milk into a glass and continued to do that until you ran out of glasses or milk, you'd have converted a signal into bits. I also covered how a partially filled glass was neither full nor empty and if you ended up with milk all over the desk you wouldn't know how much there was.
<p>
In terms of electronics, how does this actually work?
<p>
In essence you're comparing a reference voltage against your incoming antenna signal. The way that happens is you have a series of resistors between ground and your reference voltage. For simplicity, lets say five identical resistors against a reference of 5 Volts. The result is a series of steps of voltage. At the first resistor the reference voltage is 1 Volt, at the second, it's 2 Volt and so on.
<p>
If you were to compare your antenna signal at the first resistor, you'd compare it against 1 Volt and your antenna signal might be higher or lower. If it's higher than 1 Volt, we'd record a full glass or one and if it's lower we'd record an empty glass or zero.
<p>
This is done with a nifty circuit called a comparator that compares two voltages. If the signal is higher than the reference, it returns a one and if it's lower, it returns a zero. If that sounds familiar, an op-amp does a similar thing and if you're wondering, a comparator is an op-amp without a feedback resistor.
<p>
In a circuit diagram you might see a triangle with two voltages coming in, the one you're measuring and the reference voltage with a single output that's either zero or one. Inside that triangle, which you can purchase as a component for cents, you'll find the whole circuit that makes all this happen.
<p>
I'll acknowledge there is an opportunity here to go into how an op-amp actually works, how it slightly differs from a comparator and more, but we're talking about an Analogue to Digital Converter, which in turn is part of a discussion about how a Software Defined Radio works, so I'll leave the circuit diagram and building an op-amp from basic components for another time.
<p>
One thing to note though is that this type of ADC is essentially independent of frequency, it's a direct-conversion ADC and the speed of sampling is determined later on in the process.
<p>
Back to comparators. We have several of these, each comparing the incoming signal against a stepped reference voltage. In actual fact, if you're doing 8-bit sampling, you'd need 255 of these comparators, if you're sampling at 16-bits, you'd need 65535 of them.
<p>
As I explained with glasses of milk previously, you'll have interesting results if the voltage you're measuring is between steps. You could increase the number of steps and measure more accurately, but as I said before, you're only kidding yourself if you think that solves the actual problem.
<p>
In the same way, if the voltage you're measuring is higher than the total reference voltage, you're up the creek without a paddle and you won't know what happened, unless you saw magic smoke appear, in which case you know that lightning probably struck somewhere nearby.
<p>
You could increase the reference voltage, like making the glasses bigger, but that's actually making it worse, since we now have bigger steps between each measuring point.
<p>
So, a flash ADC is a series of comparators which compare an incoming signal against a reference voltage and returns a series of bits that digitally represent your signal.
<p>
The final piece of the puzzle is how we get from the bits coming out of the pile of comparators to the byte going into your computer. Basically we're tallying each bit, that is, we're counting how many there are and returning the number as a value to the computer. The speed of this counting process is what determines how fast we can measure our signal.
<p>
Did I mention how deep the rabbit hole goes? Amateur Radio for me is the gift that just keeps giving, more to find every time you look.
<p>
I'm Onno VK6FLAB
Listen:
Milking Software Defined Radio
Foundations of Amateur Radio
<p>
One of the unsung hero components of a Software Defined Radio is the A/D or Analogue to Digital converter. Its job is to convert the analogue signal that's coming in via the antenna into a digital signal that is processed by software.
<p>
I've talked about the difference between analogue and digital before and many explanations talk about converting things into zero and one. There are a few steps before that.
<p>
Imagine a row of identical glasses, let's say eight. Grab a jug of milk and pour it into the first glass. Keep pouring until it's full. Now do the same to the second glass, rinse and repeat until you either run out of milk, or run out of glasses.
<p>
You now have either a row of glasses full with milk and some spilled all over your desk, or you have some full glasses and some empty ones.
<p>
Now if you were to mark a one on your logging paper for every full glass and a zero for every empty glass, you'll end up with a row of zeros and ones. Essentially you've converted an analogue signal into a digital one and in effect, this is how an A/D converter works. Each glass represents effectively what's known in computing as a bit. Grab eight of them and you have a byte.
<p>
I will point out that this is just one example of an A/D converter, there are many others.
<p>
You may have noticed I've skipped over some interesting things here.
<p>
For example, what happens when you spill your milk all over the desk? Or what happens if you don't completely fill a glass?
<p>
This is the bit where the action is.
<p>
So, let's look at that.
<p>
If you've ever over driven a microphone or a speaker, heard of clipping, or distortion, those are all equivalent to spilling milk all over your desk. The take-away is that there is an indeterminate amount of milk and no place to store it, so your row of glasses says all full, but you and I both know that there is some spillage. This is lost information, we don't know if there is a droplet spilled or a whole ocean spilled.
<p>
So, one consideration in picking an A/D converter is how to deal with high signal levels. You may need to either increase the number of glasses, or bits, or you may need to decrease the signal before measuring it.
<p>
Another interesting thing is what happens at the boundary between full glasses and empty glasses. If you pour one glass full and run out of milk, you're good to go, but the reality says that you'll start pouring the next glass and you'll run out, having a glass that's only half-full. Or is it? Is it half-empty? How do you know? Is this glass represented as a one or as a zero?
<p>
You could create a row that's twice as long with glasses that are half the size, and at the boundary you'd have a more accurate idea, but you'd still have the same issue, is the glass that you filled only partly, half-full, or half-empty?
<p>
There's more to come, but the basic idea of converting an infinitely variable signal coming from your antenna into something used by software is a big part of a Software Defined Radio.
<p>
I'm Onno VK6FLAB
Listen:
When digging gives you more understanding, the magic of software.
Foundations of Amateur Radio
<p>
Today I'm going to go sideways to move forward. In amateur radio we consider circuits, components such as transistors, inductors, capacitors, crystals and how they're connected to each other. The framework in which that exists is embodied by the field of electronics and how these components can be mixed together to shape a radio that you can build or buy.
<p>
In a software defined radio there are electronics and components to be sure, but the bulk of the work is done in the field of software and today I'm going to look at that.
<p>
Computers surround us, in our work place, in our home, on the street, in our hospitals, across our society. Each of these devices is running a thing called software, as opposed to hardware - a physical thing, software is intangible, in much the same way as your date of birth is intangible. You cannot hold your birth date in the air and point at it. You could write it down onto a piece of paper and point at the piece of paper that has the date on it, but you'd be pointing at a piece of paper, not your actual birth date.
<p>
Computers work in much the same way.
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You cannot point at software, nor can you hold it in your hand. You can print it out onto paper, and point at that, but you'd end up with a deforestation problem that far exceeds the stripping of all the trees in the Amazon rain forest. To make matters more complex, there are at least two types of software, human readable and computer readable. You can translate human readable source code into a computer readable executable with a tool called a compiler, but doing it in the other direction is much harder.
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Think of the ink on the paper that describes your date of birth. You can put the ink on the paper, but putting it back into the pen is more complex.
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All this is leading somewhere, I promise.
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A little while ago I started digging into how Software Defined Radios work and if you've been following along on my journey, there'll be parts that you can follow, parts that you sort of get, and bits that seem like black magic. This will be different for each person. My black magic is not going to be the same as yours and the things I understand without thinking might make your head explode. If that's not enough, the goal posts keep moving.
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As I said, I started digging, much like peeling an onion, removing layer by layer, I've been exploring and learning and hopefully sharing my excitement along the way.
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The other day a mate of mine came by with a new toy. A QRP or low power HF radio. The device itself is entirely driven by software, that is, it's a Software Defined Radio. It has some knobs and buttons, a display, a power socket, a plug for a microphone, an antenna, a speaker port and some other bits and pieces, but underneath all that is software.
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What's special about this radio is that the software is Open Source, that is, you can peek inside and see what the code looks like before it becomes ink on the page, the human readable source code, rather than the computer readable executable.
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I've touched on Open Source before and perhaps I should spend some time on that soon, but for now, think of it as a set of rules that dictate how you are allowed to use source code.
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As any self-respecting IT geek, I went to the website where the software is available and downloaded it.
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What struck me was that it was much simpler than I had expected. Don't get me wrong, this is a complex piece of software, not something I'm expecting to pick up in an hour or even a week, but it's simple - as in digestible. I can point at different bits and understand what they do. This part does Morse Code, that does FM, over here is RTTY and look, over here is FreeDV.
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If you're wondering, I'm describing the UHSDR, or Universal Ham Software Defined Radio project. Built originally by Chris M0NKA and Clint KA7OEI and sporting an impressive list of contributors, this software offers insight into receiving and transmitting using an SDR across a variety of amateur radio modes, including SSB, AM, FM, Synchronous AM, FreeDV, RTTY, CW as well as CAT or Computer Aided Transceiver, sometimes referred to as rig control or remote control, a way of using an external computer to control a radio.
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The beauty of this software lies in its simplicity. Unlike many other projects, there is no code dealing with Windows, or with Mac OS, there is no mouse, touch screen, or any other complex user interface. There is a limited set of buttons, a few dials and a screen for output. The end result is that the level of complexity is much lower than you'd find if you were to start digging into something like PowerSDR or some other code-base.
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The point is that the UHSDR project is a really accessible way to start digging into the software behind a software defined radio and another path into this magical hobby of amateur radio.
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I'm Onno VK6FLAB
Listen:
Software Defined Radio offers another path to the same information.
Foundations of Amateur Radio
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Over the past few weeks I've been describing how some of the fundamental concepts of software defined radio work and how some of these operate and interact with each other.
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You might think of some of these ideas and technologies as unrelated to the hobby of amateur radio, or not relevant to traditionally built radios.
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Nothing could be further from the truth.
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Before I go on, I've been trying to find more elegant terms to distinguish between radios built with mostly software and those built with mostly hardware, and I use the word mostly, because a traditional radio like my Yaesu FT857D has software on board and similarly the software defined radio Flex 6600 has traditional components inside the box.
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For convenience, until I find a better distinction I'm going to refer to these as hardware radios and software radios. When I refer to a hardware radio, think Yaesu FT857D, when I say software radio, think Flex 6600.
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Back to the topic at hand. The techniques used in both disciplines, hardware and software, apply to each other. So for example, a band filter might be useful in both and use similar if not identical circuitry, but a noise filter, or an audio filter like a Collins SSB or CW filter might only exist in a hardware radio and the software radio deals with the issue using little programs.
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Similarly, the local oscillator in both determine the accuracy of frequency representation, but a hardware radio might require a screwdriver to adjust, where a software radio offers the adjustment functionality with a single menu option.
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With my time spent on software defined radio, I'm finding that my understanding of how spectrum relates to the signal and how filters, offsets and various adjustments all relate to each other.
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Don't get me wrong. The things I'm learning are perfectly able to be represented within hardware radios and the education that goes with that, what I'm saying is that they arrived for free for me with understanding the software defined radio.
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Let me give you an example.
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If you listen to a Morse code beacon signal on the 10m band, lets say the NCDXF beacon on 28.2 MHz. If your radio is set up correctly, you'll hear a tone as each beacon does its thing.
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If you tune slightly off frequency, the tone changes, up or down, depending on how you've got your radio configured.
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If you've got a Collins CW filter, you might find the whole thing vanishes if you stray too far off frequency.
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Now here's the thing.
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The tone you're hearing is actually dependent entirely on how far off frequency you are, so much so, that if you're entirely on frequency, you won't hear anything at all.
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But you just heard me say that if your radio is set up correctly, you'll hear Morse if you're on frequency, and that's because, setting up the radio includes an offset, in a hardware radio it might be called the CW pitch, and what it does is essentially take your radio off frequency by the pitch amount.
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You can test this by setting the pitch to 0 and taking the radio off frequency by say 500 Hz.
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The point is that how this works and my understanding of it, came entirely from the software radio side. My training didn't include the intricacies of hardware radios, but my curiosity got me there by another path.
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Another way to consider the Morse code signal is to think of it as a tone of 0 Hz. You can't hear the tone, since it's 0, but if you were to move the dial, the 0 changes into something you can hear.
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While I'm at it, if you've ever wondered what's the difference is between the two CW modes on your radio, when they don't appear to do much at all?
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Consider two signals, side by side, say 500 Hz apart. From a listing perspective, the station you care about is at 500 Hz and the one you don't care about is at 1000 Hz. Change to the other CW mode and the one you care about is still at 500 Hz, but the other station has moved from a 1000 Hz to 0 and it vanished.
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I've spoken to many different amateurs over the years and each one learns their craft differently.
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I hope that my weekly podcast adds little puzzle pieces to your mind that will over time collide with each other and end up with that elusive Ah-Ha moment that makes you smile with a tinkle in your eye and a better understanding of this amazing hobby.
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I'm Onno VK6FLAB
Listen:
Digital Origami in Software Defined Radio
Foundations of Amateur Radio
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As a quick recap of what I've discussed before, a Software Defined Radio is a tool that essentially measures the voltage at the base of an antenna system and sends that to a computer for processing.
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The faster you measure, or sample, the better the representation of what's coming in via the antenna. The traditional view is that you need to sample at least twice as high as the highest frequency you want to represent.
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You may also recall that an antenna system doesn't just receive a single frequency, the one your radio is tuned to, but all frequencies.
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So, if you need to build a software defined radio from scratch, your first question might be: What do I want to listen to?, followed by: Which sample rate do I need?
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If we were to answer the first question with HF, say up to 50 MHz, the answer would be something like a sample rate of 100 MHz, so you can capture any signal up to 50 MHz.
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So, twice the highest frequency as the one you care about, that's the short way of waving your hands about and ignoring any little inconvenient side effects.
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Like, what happens to signals above 50 MHz?
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First of all, your antenna system will still receive those signals to more or lesser degree, they don't just vanish because your sampling tool isn't interested in anything over 50 MHz.
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The second thing that happens is that the signals between 50 and 100 MHz will turn up backwards between 0 and 50, so you'll effectively hear 51 MHz at 49, 55 MHz at 45 and so on.
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As a neat little side-effect, for those reversed signals, an upper side band signal will turn into a lower side band signal and vice-versa, but I'll leave that for another time. In case you're wondering, yes, this can be a desired effect.
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The signals between 100 and 150 MHz will also turn up where they're not welcome, 105 MHz becomes 5, 110 MHz becomes 10 and so on.
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A different way to picture that is to think of a tri-fold birthday card. Lay it flat on the table, put a 0 in the top left, 50 at the first fold, 100 at the second fold and 150 in the top right. You're looking at 0 to 150 MHz.
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Now fold it up.
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You'll notice that 0 and 100 are in the same place and 50 and 150 are also in the same place. If you need more detail, put some in-between numbers, 25 MHz, 75 MHz and 125 MHz and you should see what's happening.
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I've seen it described as digital origami and it is. The technical term is called aliasing and it's also referred to as folding. It happens in day-to-day life as well. If you've ever seen a wheel running backwards on television or on a film, that's an example of folding.
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If that's not enough, this phenomenon repeats itself, 150 to 200 MHz is overlapped in reverse, 200 to 250 MHz overlaps normally and so on.
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You might come to the conclusion that your magic SDR isn't so magic any more, now you have all this other stuff turning up that you don't want to hear. So what do you do?
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One approach is to increase the sample rate, but as I've explained, it doesn't make the problem go away.
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But here's the thing: If you were to sample at say 200 MHz, you'd be perfectly fine with any signal up to 100 MHz.
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Now here's the kicker.
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If you filter out anything above 50 MHz, and as long as there's nothing left by the time you get to 100 MHz, you're good to go, no more unwanted information, no more aliasing or folding.
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Essentially what you've just done is created a thing called a bandwidth limited system. You've essentially removed anything above 100 MHz and now your sampling is working as planned and all of the stuff I've said about sampling at least twice the maximum frequency applies.
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Yes, there's more, but I'll get to that another time, but to give you a taste, what happens if you want to use the same SDR to listen to the 2m band?
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I'm Onno VK6FLAB
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Listen:
SDR: How many colours inside a Software Defined Radio?
Foundations of Amateur Radio
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If you were asked to make an image of the Sydney harbour bridge and only use four dots, the viewer might struggle to determine what was the bridge, the sky, the water and the Sydney Opera House. Regardless of the number of colours available to you, the number of dots would not be enough information for most people. You might have a nice piece of art on your hands, but it might be ineligible for the Archibald prize. Even if you were allowed many colours, and just four dots, figuring out if the blue dot was water, sky, or the background of the Australian flag on top of the bridge might be just as complicated.
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If you were asked to make the image with one hundred dots, and only use black and white, from the perspective of the viewer you'd have a result that was easier to understand. Use a thousand dots, even easier, even if you only used black and white.
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Now, if you were to use a hundred dots, with ten colours, your image might be just as easy to understand as if it was a thousand dots in black and white.
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The point is, there are two things going on here. The number of dots and the information contained in each dot.
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More dots or more colours, or both, will help your image.
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Similarly, in Software Defined Radio, more dots, that is, more samples, will help and as I've previously mentioned, you need at least twice the number of samples as the highest frequency that you're measuring. But what of the colours in relation to an SDR?
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Measuring voltage as a human with a piece of paper is pretty straightforward. Provided you've got a Volt meter, a piece of paper and a scribble stick, you're good to go. If you measure your voltage as 1 Volt, you write 1, if it's -1 Volt, you write -1. Similarly, if it's 100 Volts, you'd write 100, 13.8 Volts and you'd write 13.8. We'll get back to colours in a moment.
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Provided your paper is big enough, you can record as many values as you need and as accurately as you desire. 13.8 or 13.8853, makes no difference to a piece of paper.
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Computers represent numbers internally using powers of two, called bits. A single bit can represent two values, 0 and 1. Two bits can represent four values, 8 bits represent 256 values and 16 bits represent 65536 different values.
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The takeaway is that there are a specific number of values that you can represent inside a computer, depending on how many bits you use.
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Consider the values I've mentioned, 1, -1, 100 and 13.8. That's four different values. If it's not immediately obvious, what ever solution you come up with, tracking positive and negative, tracking small and large, whole and fractions should all be part of the mix. In case you're wondering, we're essentially describing here how many colours or values we are going to allow, or in terms of a computer, how many bits.
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Let's consider all the values you might measure and represent inside a computer. How many different voltages do you want to be able to record between 1 Volt and 100 Volt?
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If you allow for ten values, you can record 10 Volt, 20 Volt and so-on, but you can't record 15 Volt.
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If you allow for a hundred values, you can record 1 Volt, 2 Volt and up, but you won't be able to record 1.5 Volt.
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If you account for a thousand values then you can record 1.1 Volt, 1.2 Volt and so-on, but you can't record -10 Volt.
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Remember, our computer representation can only manage a specific list of values and the size of the list is determined by the number of bits you're using.
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The rabbit hole goes even deeper.
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Radio signals vary massively in their strength, which is why we use a decibel scale to represent the signal strength, instead of saying station A is a thousand times stronger than station B, we say it has a signal level that's 30 dBm higher. That's comparing a 1 Watt station to a 1 kilowatt station, and in terms of voltage, that's between 20 Volt and 632 Volt.
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If you're designing a mechanism to store your measurements inside a computer, you might decide to use dBm to record your measurement. Let's say 30 values from 30 to 60 dBm. Sounds great, where do I sign up?
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Not so fast. What happens if our station is running less than 1 Watt, or if it's running 100 kilowatt, like when you happen to receive a nearby FM broadcast station?
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Not only do you need to contend with a whole range, called a Dynamic Range of measurements, you also need to deal with what happens to the overall picture.
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Let me say that in another way.
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Your voltage measurements at the base of your antenna are a representation of the RF information that your antenna is receiving, or transmitting for that matter. Representing that inside a computer means that the values you're using, and how fast your gathering them, determine how well the RF signal is represented.
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One thing to note is that the largest values represented by what ever you choose is only part of the problem.
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A signal that is stronger than the largest value you can record is not going to be recorded correctly. Similarly, a signal that is so small that it doesn't register as a change, also has an incorrect recording.
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Picking the right combination of dots and colours, sample size and bit-depth, doesn't end there, because there's even more to this, but I'll leave that for next time.
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To blow your mind, the Dynamic Range, bit-depth and sample size I've talked about in relation to Software Defined Radio, also applies to many other things, like taking a photo with your digital camera, or sampling digital audio, so understanding this in one area will likely help you in other places as well.
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The final takeaway is that a computer records a range of values that can represent a measurement in the real world. Picking the correct range of values determines how well your computer represents what your measuring.
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I'm Onno VK6FLAB
Listen:
SDR Sample Rates: How fast is fast enough?
Foundations of Amateur Radio
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If you measure the voltage at the base of an antenna and record the readings, you end up with a collection of numbers that represent the voltage over time. These numbers, or samples, can be used to represent the antenna signal inside a computer.
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An antenna system voltage is an example of an analogue signal, continuous over time, the recorded readings, the samples are an example of digital, discrete and intermittent.
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It's possible to reconstruct an analogue signal from digital samples and that's exactly what Software Defined Radio or SDR is all about.
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The process of sampling essentially converts a continuous signal into an intermittent one. As recording separate samples implies, there is loss of information in this conversion.
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For example, if you sample once a minute, you'd represent a continuous signal as 60 samples per hour, probably enough to reconstruct where you've driven in your car along the highway, but hardly enough to reconstruct the route through the middle of the city, let alone represent an antenna signal that varies millions of times per second.
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So, how often do you need to record a sample?
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Turns out that if you sample at least twice as fast as the highest frequency you're representing, you're good to go.
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So, for sound, the human ear can hear about 20 kHz, so more than twice that, explains some of why a CD is sampled at 44 kHz.
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If you want to represent the 20m band, up to 14.350 MHz, you need at least a sample rate that's double that, or 28.7 MHz.
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As an aside, there are other ways to look at this problem. If you managed to move the 20m band down to 0, then you'd only need at least a sample rate of 700 kHz to do this.
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Let me say that in a different way.
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The width of the 20m band is 350 kHz. So sampling it would require at least twice that, or at least 700 kHz. Moving frequencies around is something that we've been doing in traditional radios for a long time. The technique uses one or more frequency mixers. This means that combining some traditional radio tools with an SDR gives you even more options.
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Truth be told however, this idea of moving the band with one or more mixers is becoming less important as technology improves and there are plenty of reasons not to use this. I'll talk about that at another time.
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So, the first takeaway is that to sample a continuous signal and be able to represent that signal accurately requires a sample rate that's at least twice as high as the highest frequency in the continuous signal.
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Without going into the actual proof of this, consider a sine wave that oscillates at 1 Hz. If you sample it at anything less than 2 Hz, you'll end up with some cycles being sampled only once, which isn't enough to represent the sine wave. If you sample it at exactly 2 Hz, you'll have two samples on every cycle, but if you happen to sample when your signal is 0, all you'll ever measure is 0. By sampling at a rate greater than 2 Hz, you overcome that limitation.
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I'll make brief mention of another phenomenon, that of over sampling. An interesting thing happens if you sample twice, three times or more than the minimum sample rate. In short, the higher sample rate improves the dynamic range, noise performance and filtering, all very useful when you are processing radio signals. Cheaper and cheaper hardware are making this very attractive and it explains some of the reasons why SDR manufacturers are using sample rates that far exceed double the highest frequency being sampled, for example, the Flex-6600 samples at 245.76 Mega Samples Per Second, or Msps, even though the maximum receive frequency is between 30 kHz and 54 MHz.
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In case you're wondering, yes, I'm leaving out a lot of detail here, one thing at a time.
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The opposite, under sampling, has its uses as well, but I'll also leave those for another time.
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The second takeaway is that higher sample rates are used to reduce cost, increase performance and reduce component count.
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Some of what I've talked about can be explored with the popular RTL-SDR USB dongle which is actually a mass produced commodity digital television receiver, made in the millions and accessed directly thanks to the combined efforts of many different people. If you'd like to start to play, $25 should get you a dongle and most of the software you can start to experiment with is free. Check out rtl-sdr.com to get started.
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If you'd like to get in touch, please do, cq@vk6flab.com.
<p>
I'm Onno VK6FLAB
Listen:
Software Defined Radio is fundamentally a different way of looking at radio spectrum
Foundations of Amateur Radio
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We think of radio as operating on a specific frequency. We select an antenna resonant on a single band. We configure the radio for that same band and then turn the dial or the VFO, or Variable Frequency Oscillator to a particular frequency within that band.
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All of our language is geared towards this concept of tuning, of picking out, selecting one special tuned, resonant frequency and listening to it.
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I've said this before, but that's not actually what's happening.
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Your radio is receiving all RF frequencies, all of them, all at the same time, all the time. Your antenna is better at hearing some frequencies than others, but that doesn't stop it from hearing everything at once. Your radio is getting all that RF information at the antenna connector. After that, every step along the way is removing unwanted information, first it removes all the bands you're not listening to, then the VFO selects which part of what remains to let through to the decoder and the result finally arrives at the loudspeaker.
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Ultimately, all your radio lets you play with is what's left over. Say about 3 kHz bandwidth. Using traditional radio, if you want to listen to two repeaters, you either need to switch back and forth quickly, or you need two receivers.
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Now without going into how precisely, imagine an SDR with a bandwidth of 3 MHz, one thousand times larger than your traditional radio. Before you think I'm being fanciful, a $25 gadget can do this. This means that you could process most if not all of the 2m amateur band and then pick out which bits you'd like to decode. You could decode all the local FM repeaters, an overflying satellite, the International Space Station SSTV, a beacon, Morse, Packet, RTTY and simplex contacts, WSPR, APRS, EME, whatever is happening on 2m, all at the same time.
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Let me say that again. All of the 2m band, all at the same time.
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The point is that all this information is there, all the time. We can opt to decode or ignore the information. In a traditional radio, you can only decode one signal at a time, but on an SDR, you can extract as much or as little as your computer can handle. Some SDR language talks about using multiple receivers, but a better description is multiple decoders.
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This means that software defined radio is fundamentally a different way of looking at radio spectrum. Instead of filtering out everything we don't want to decode, we select which decoder to apply to which part of the spectrum.
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With an SDR you could represent the 2m band as a 3 MHz slice of spectrum as a series of measurements. There is no loss if you reuse the numbers, so if you process the same data multiple times, you have no loss of signal, no deterioration, no extra noise.
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All we do is feed the same data into each decoder, pick out the bit we want to decode and have at it.
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There is a misconception that you need serious computing power to do this. That's not strictly accurate. A $5 Raspberry Pi single board computer is more than powerful enough to do this. You can argue that this is serious computing power, compared to what we used to land on the moon it is, compared to your mobile phone, it isn't.
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I fully intend to go into the maths behind this, but it's not scary, despite what you might think or have been taught. My week has been about the maths and it's become clear to me that there are lots of explanations around, each trying harder than the next to scare you away.
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If you feel the need to run screaming for the hills when you hear the words Nyquist, Shannon and Fourier, then get it out of your system and come back when you're ready.
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I'd like to mention that I've been working on how to explain this over much of the week, I've lost count of the number of drafts I've written, but it keeps coming back to the words that are almost as old as I am: My god, it's full of stars.
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No doubt you might be convinced that I've lost my marbles and that I'm going well outside the Foundations of Amateur Radio, but I have to confess, this is what radio is today, and I'm thrilled to be here learning more about how this all works. Hopefully you are just as thrilled.
<p>
I'm Onno VK6FLAB
Listen:
How does a Software Defined Radio or SDR work?
Foundations of Amateur Radio
<p>
If you've been around the hobby in the past decade, you may have come across the invention of a Software Defined Radio, or SDR. You might even own one and if you've looked into how it works, read the explanation that essentially describes it as a traditional radio where all the components are implemented in software. To me that's like explaining how a radio works by waiving your hands and saying: here is magic.
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How it actually works is something all together more interesting and thought provoking.
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If you think of sound, like my voice, coming from a speaker, you can imagine putting a volt meter on the speaker terminals and measuring every second what the voltage is. As my voice gets louder you might measure a large voltage, as I take a breath, it will be smaller. You could chart the different measurements and show a waveform that would represent the loud and soft parts of what I'm saying. The faster you measure, the more accurate the picture represents my voice. For comparison, a CD player does this measurement 44 thousand times per second.
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If you were to play back those sound measurements at the same rate into a speaker, you'd end up with my voice, and that's actually more or less, what's happening if you're listening to this podcast. Yes, for the purists, there's more to it, but not relevant at this point.
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Similarly, if you were to hook up a volt meter to an antenna and take measurements, you'd end up with a chart that represented the signal strength that your antenna is receiving and the faster you measured, the better the representation. What it exactly represents I'll come to in a moment.
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The waveform that represents my voice is actually a very complex signal. In much the same way as a piece of music is made up of different notes, played in sequence and in concert with each other, my voice is also made up of separate frequencies, played together to form the words that you hear.
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If you were to measure those separate frequencies and draw a waveform for each, you'd see how every one contributes a little to the overall effect, and if you were to add them all together, you'd have my voice again.
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In the same way, the waveform that represents an antenna signal is made up of all the separate frequencies that go into the overall signal. You might be surprised to learn that an antenna is actually hearing all frequencies at the same time. Some better than others, but typically, all of the RF spectrum at any given time.
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Your radio is also essentially hearing all frequencies. When you tune to a local station on 720 kHz, you're actually telling your radio to ignore all the stuff that isn't 720 kHz and to only process that small bit of what it's hearing. The selectivity of a radio is the measurement that represents how good your radio is at being deaf to all the things you don't want to hear.
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To help that filtering, a traditional radio and antenna works by pre-selecting part of the RF spectrum, when you press the AM button on your car-radio, you're selecting which chunk to listen to, press the FM button on the same car-radio, you'll select another chunk. On an amateur radio, you select by choosing the 80m band, the 40m band, etc. Similarly, your antenna is pre-disposed to hearing a particular chunk better than others, but that doesn't make it immune to signals across the entire range.
<p>
You may have heard described that a Software Defined Radio hears all frequencies at the same time. Essentially it's a volt meter connected to your antenna, spitting out measurements as fast as it can for processing by a computer.
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The waveform that comes from those antenna voltage measurements represents all of the RF spectrum and it's just the beginning of what you can do next.
<p>
In the same way that my voice is made up of lots of different parts, all played together, the RF spectrum is made up of the local broadcast stations, the local TV stations, mobile phones, garage remotes, Roy on the 7130 DX net, this podcast on your local repeater, all at the same time, all played together, to make the waveform that represents the measurements you make at the base of an antenna.
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I'm going to ignore for a moment how exactly we extract the various bits, or how we decode an FM or SSB signal using software, it involves some math, instead we can look at something that is easier to explain.
<p>
Unlike with a traditional radio, which has to work hard to filter out undesirable information, a software defined radio can filter out information by just deleting those measurements you're not interested in.
<p>
Yes, there is more to it, much more, but that's the beginnings of how an SDR works.
<p>
If you'd like to get in touch, please do, cq@vk6flab.com.
<p>
I'm Onno VK6FLAB
Listen:
Antennas out of sight and out of mind ...
Foundations of Amateur Radio
<p>
Previously I've spoken about the dynamic nature of your station. Even if from day to day use, nothing changes, things around you are always in flux. Propagation changes, power fluctuates and the environment in which your antenna operates is dynamic. Mobile stations even more so.
<p>
A few days ago we had a gale come through, strong enough to do some major damage, rip off some roofs, break some trees, cause flooding, cause power outages, plummeting temperatures, the first of the Winter Storms.
<p>
Obviously, checking out your antenna after such an event is expected. Better still, stowing your gear before the event is even better.
<p>
Such extreme weather events are an obvious trigger to attending to antenna health and well being, not to mention, maintenance and repair.
<p>
The thing is, it's not the only time you should check out your antenna. Every day it's subject to change. The sun rises in the East, follows its path along the sky and eventually sets in the West. The temperature and humidity change throughout the day and continue to change through the night and the next day it starts all over again.
<p>
Peppered with sun, rain, snow, salt, corrosion, expansion and contraction, your faithful antenna sits there ready for you to get on air and make noise, until one day it isn't.
<p>
You could just wait until it falls down, dies, perhaps becomes a hazard to anyone within gravity range, not to mention, destroy your radio when you key it up. Or you could check your antenna regularly and look after it. Inspect and test it regularly, run you analyser across it every couple of months, you know the drill.
<p>
Most antennas are out of sight for most of their life, but they should never be out of mind.
<p>
During the weekly F-troop net we started discussing this - as well as an in depth conversation about launching wire into trees - and there were several suggestions worth investigating.
<p>
One amateur pointed out that the level of complexity in the air dictates the amount of maintenance. A log periodic antenna on a rotator needs more Tender Loving Care than a wire hanging off a tree.
<p>
Another suggested that you should regularly check the tower supports - technically the mast supports - a tower is self-standing and a mast is not - the best way to remember is that is the Eiffel Tower doesn't have any guy wires.
<p>
Before a storm, if you have warning, you should check the supports, wind down anything that goes up and down and you should think about how you're going to earth the coax. I've previously covered the weirdness that lightning and charge represents, even at distance, so don't wait until it's overhead.
<p>
There were suggestions of using spark plugs and Mason Jars, but I've got no supporting evidence either way. My geek background is sceptical, but I'm open to learning more.
<p>
I've seen installations where a coax switch is used where the antenna is switched to a shorted socket, so the inner and outer braid of the coax are connected to each other.
<p>
One amateur suggested that an antenna tuner is cheaper than a radio, and that if you leave it in place during a storm, blowing that up is cheaper than blowing up a radio, but your mileage may vary. Also, if you have spare cash to burn, I'm happy to take your donation and relieve you of that fire hazard.
<p>
It's interesting in and of itself that antenna maintenance is often discussed in terms of extremes, lighting, storm, wind, ice, etc. and less so in terms of regular maintenance.
<p>
Finally, if you're only using a temporary antenna, you're not exempt from this. You're actually likely to have more failure, since the act of erecting and lowering of the antenna is likely to cause more wear and tear.
<p>
The antenna is the final part of the transmission chain and it should be treated with the same respect as the power supply at the other end.
<p>
I'm Onno VK6FLAB
Listen:
Fragility of Communication
Foundations of Amateur Radio
<p>
Our day to day life is full of communication. We listen, although less and less, to the radio for news and entertainment, sometimes mixed together as food and games for the masses.
<p>
We can communicate with family, friends and the rest of the global population using a telephone. With the internet as a transmission medium, we exchange text, sound and vision with impunity to anyone who stumbles across it on a mind boggling collection of outlets, websites, social media, email, streaming services to name a few.
<p>
The vast majority of this kind of communication is a commodity, that means that with little or no training most of the population has access to this.
<p>
Another aspect of this commodification is that it's reliable. It works most of the time, it's generally good quality, with little or no loss, as in, you speak into your phone and there's an extremely high chance for the other party to hear your voice. While there are occasions that calls drop out, or the audio is chopped up, it's more an exception rather than a regular occurrence.
<p>
In stark contrast, amateur radio is none of those things. It's not a commodity, it's not reliable, it's a poor man's version of the ubiquitous mobile phone.
<p>
As amateurs we know why it's not the same, for starters, to make contact between say Perth and Bermuda using amateur radio requires exactly two pieces of equipment. Your radio and theirs. Making this contact with a mobile requires that both ends have a phone. They'll also need a way to connect to the phone network, either a local base station or a telephone exchange, those in turn connect via many different ways to each other, including repeaters, relays, perhaps a satellite, a fibre optic cable or three, too many devices to count today. Extreme level of complexity.
<p>
I'm mentioning this because it's simple to conclude that amateur radio is obsolete, but its just not true.
<p>
With the lack of reliability associated with an amateur radio connection comes something that is unique to society today. Thanks to reliable communication, we have come to expect that all communication is reliable, even our experimental hobby, but if you spend any time on air at all you'll quickly realise that for amateur radio, we need to conduct ourselves with protocol, using specific procedures, phonetics, structured phrases, callsigns and the like to overcome some of the aspects of unreliability.
<p>
Talking on the local repeater looks and smells like a mobile phone chat room, but it's not. It relies entirely on the participants collaborating to ensure reliable communication.
<p>
Similarly, calling CQ on HF, requires that you understand that the other station isn't on the end of a telephone connection and that parts of what you're saying are going to be missing at the other end. Using phonetics, speaking slower, waiting longer and monitoring, all assist with making contact.
<p>
If you're unsure about this, just listen in on a local net for regular confusion, or use an online receiver like WebSDR to hear what you sound like at the other end.
<p>
To make things a little more interesting, every amateur band has a different failure mode. On 20m from one breath to the next, the path might close, on 80m you might get overwhelmed by noise, on 40m you might find yourself all of a sudden sharing the frequency with another station, both of you blissfully unaware of the other's existence.
<p>
Communication in amateur radio is collaborative and there are common courtesy behaviours. If you're working a rare DX station, that's not a personal friend, don't start a whole conversation about your dogs, your medical issues, or the level of amazingness of your station. You're not alone in attempting to make the contact and they're not there for your personal enjoyment. Hogging the frequency is a sure fired way to acquire the ire of your fellow amateurs, especially in marginal conditions, where band conditions are rapidly changing.
<p>
There is nothing like getting your feet wet by actually getting on air and making noise, but when you do, remind yourself that this is not a telephone and it's not perfect. Be mindful of your on-air conduct and you'll find a globe full of friends.
<p>
I'm Onno VK6FLAB
Listen:
When you hear a distress call ...
Foundations of Amateur Radio
<p>
When you get your amateur radio license you become part of a select group of humans who are required to notify authorities if you happen to hear an emergency transmission. Not only that, you're required to offer assistance.
<p>
The regulator in Australia, the ACMA, says this about it:
<p>
When a distress call is heard, you must immediately cease all transmissions. You must continue to listen on frequency. You must record full details of the distress message, in writing and if possible recorded by tape recorder.
<p>
You must also wait for a short time to see if the message is heard by a station better placed to help.
<p>
If the distress message is not acknowledged within a reasonable time, the amateur is obliged to assist.
<p>
The regulator goes on to say that after acknowledging or attempting to acknowledge receipt of the distress message, you should immediately forward details of the distress situation to the nearest police station for land based distress situations or the Australian Maritime Safety Authority for air or sea based distress situations.
<p>
In the United States, the ARRL uses the word may, rather than must, but essentially says the same thing. The FCC, the US regulator, says that an amateur station is not restricted by any rules to attract attention in the case of distress, nor is there any restriction on assisting a station in distress. In the UK, the regulator specifies that instead of waiting for a reasonable time you must wait for three minutes for a Coast Station to reply before responding.
<p>
Interestingly, getting information on how to respond, what you must and must not do is hard to come by. This in itself is a cause for concern, but let's move on.
<p>
Using the Australian example and requirements, how prepared are you to do this? Could you actually record the information, do you have a pen and paper next to your radio and can at short notice dig up a tape-recorder, or presumably some more modern recording device, capable of recording audio from your station?
<p>
Do you have the contact details for search and rescue at hand and are you actually prepared for such activities?
<p>
During the week, an amateur in Australia reported that they heard a distress signal five hours after the event. While they were at work, their station recorded off-air and they listened to the recording after returning home. Using social media, they asked the question, should they report this information to authorities?
<p>
The answer is Yes, not only should they, in this case, given that they're in Australia, they must. There was no evidence that any other station heard the distress signal, in fact, the evidence was that the other stations continued to transmit on frequency, either completely deaf, or engaged in more pressing activities like hunting for a contact.
<p>
I will note that propagation is a fickle beast and it's possible, though improbable, that the other stations on frequency didn't hear the distress call, even through it was repeated. For that reason alone, you should never assume that someone else will deal with it and as I said, in Australia, you don't get the option, you are required to.
<p>
A couple of other things came to light for that amateur this week. Their recording was in a format that was hard to process by normal audio processing software, in this case the recording was made as an I/Q recording, we should look at that some other time, but processing the file was non-trivial and valuable time was lost in uploading a huge file, and for others to download it for confirmation. There was also indecision about reporting the call to authorities and if so, to which ones.
<p>
I will say that while we don't know the outcome of the distress signal, we do know that it was reported and that at this point is exactly what is required.
<p>
The chances that you'll hear a real distress signal in your life are tiny, but if it happens, are you ready for it? I know I have some work to do.
<p>
I'm Onno VK6FLAB
Listen:
Overcoming Microphone Anxiety
Foundations of Amateur Radio
<p>
If the thought of keying up a microphone has you break out in a cold sweat, or the notion of making a mistake sends you into fits of anxiety, the idea of performance in public makes your heart pound, this is for you.
<p>
Amateur radio is a hobby of communication. The lowest barrier to entry is a hand held radio and making voice contacts with the rest of the community. There is an underlying assumption that this is likely to be the most common way that you'll start getting on air and making noise.
<p>
Of course you don't have to do that. You could learn Morse Code and never have to open your mouth. You could get a license that's permitted to use a Digital Mode like JT65 or RTTY and let your fingers to the talking. Both those options are perfectly valid and if that's what you need to get on air, be my guest.
<p>
If you do however want to actually get to a point where you can communicate with other amateurs using voice communication, then let's investigate what voice communication actually entails and what fears might be eating away at your confidence.
<p>
The most obvious fear, shared by many, if not most amateurs, is the fear of making a mistake. So let's look at that. Apart from blowing up your gear, which won't actually be noticed by anyone but you, those near to you and perhaps your bank manager, blowing up your gear is not a high embarrassment experience. Expensive perhaps, but not so much socially crippling, unless you tell someone that you did it.
<p>
Other mistakes might be a little more public. For example, if you're on HF, theoretically the entire planet can hear you, perhaps even those space aliens orbiting the Sun and in 4.367 years, those orbiting Alpha Centauri. So potentially, many different individuals and communities can hear you. To counter that I'd point out that most of those will not actually have the means to hear you, or if they technically do, they are likely to be on a different frequency, or otherwise engaged, eating, sleeping, procreating, whatever.
<p>
The chances that someone actually hears you is very, very low and if you're on VHF or UHF, the audience drops even further. The potential audience is only really line-of-sight, unless you happen to activate a Tropospheric duct, but then that might only double the potential audience, the actual audience is still a fraction compared to HF.
<p>
You might be afraid that you'll transmit on the wrong frequency. If you've purchased modern properly built and configured amateur radio equipment, the chances of transmitting out of band, into non-amateur frequencies is very low. If you pay attention to what the dial says, and you have a copy of your band-plan at hand, the chances of getting it wrong are even lower. Even so, the band police aren't going to knock on your door within the next 30 seconds, so take a breath.
<p>
The next set of fears revolve around saying the wrong thing. If you haven't talked on the radio much, or even at all, you're bound to worry about blurting out the wrong thing and being the biggest embarrassment to the hobby in this and the last century.
<p>
Getting your callsign wrong is pretty common. If you're just starting out, or even if you're more experienced, writing down the callsign on a piece of paper and having it in front of you when you key your microphone is good planning. For every contest I participate in using anything other than my own callsign, I bring a piece of paper and a thick marker for just that purpose. I can still get it wrong, sometimes I even notice.
<p>
Then there is the topic of the conversation itself. What do you talk about? How long do you talk? How much should you share?
<p>
The answer to those questions can be summed up with a simple phrase - less is more. If you're establishing the actual contact, a bare minimum is required. You need to first establish that you have their callsign and they have yours. Don't do anything until both those have been confirmed. That goes for both day-to-day contacts and contest contacts. After that, establish how well they are hearing you and how well you are hearing them. Exchange a signal report. If you're in a contest, you'll include the contest exchange while you're sending a signal report.
<p>
If you're not sure about anything, you can stop there. If you're doing a contest, that's all that's needed and unless the other station asks for your dog's name, or the weather, you can safely move on to your next contact.
<p>
Your takeaway from this should be that doing a contest can be a really safe way to start. There is minimal information to exchange, it follows a strict format and it's generally over before you know it.
<p>
Working DX, chasing activators in far away lands can be your next stepping stone, or joining a net on the local repeater might be how you next cut your teeth.
<p>
You can create a list of things you've heard other people mention and use it to describe your environment. Nothing wrong with making some notes.
<p>
Most amateurs perpetually carry around a little notebook to scribble down callsigns so when they're in a group discussion, they can track who's on and who's next.
<p>
As you can tell. You can make this as simple or complex as you like. You can be afraid of the sky falling in, but then you'd need a Druid, a shield and a menhir and if you can swing it, a buddy called Asterix.
<p>
Final comment. If all else fails, pretend you're talking to me. I can tell you that I'm happy to make the contact, I'm all ears and if I hear you, I'll respond. Did I mention that I'm standing on my head and I'm not wearing any clothes?
<p>
So have at it.
<p>
What are you afraid of?
<p>
I'm Onno VK6FLAB
Listen:
The Station Log
Foundations of Amateur Radio
<p>
A topic that rarely if ever gets any serious air-time is the humble station log. It's a process where you track what contacts you've made with whom, when and what conditions prevailed at the time.
<p>
Notice first of all that I mention that it's a process. A station log is made up of several different moving parts and if you're new to this you might think of your station log as a physical thing. You can actually buy things called Station Logs, looks like a book, it has pages, lines, columns, sometimes pre-populated with headings and as you operate, you write stuff into this book.
<p>
Let's start with the stuff. What stuff? How much stuff?
<p>
Have you ever heard another station on-air say something along the lines: Hey Wally, it's been a long time, we last spoke in 1984, how are you and how are the kids?
<p>
If you thought for a moment that the station had all that information stored away in the back of their mind, that's not to say, some do, but most of the time it's thanks to their station log that this kind of information is at their fingertips.
<p>
Another thing you might realise is that if you're using paper, like the book I mentioned, then doing this kind of lookup is less than trivial, unless you maintain two logs, one in callsign order and another in contact order. Perhaps you start creating a card file with this kind of information.
<p>
We do have better tools.
<p>
At the simplest level, you can create a spreadsheet with your station log. It's simple to maintain, easy to expand, backup, infinitely flexible and for many stations it ticks all the right boxes as a way to store contact information.
<p>
So, looking at a spreadsheet, what columns should you introduce as a starting point?
<p>
Well date and time is a good start. Logging in UTC is a solid idea, given that you might move location several times in your amateur career and you might not always be in the same time zone, so if you need to know what time it actually was, you'd need to add a time zone column. Instead just log in UTC, and the time will always be correct. After date and time, you'll need a record of the frequency. You can either record it as a band name, or as an actual frequency, your choice. You'll need a column for the mode, was it an SSB contact, CW or an AM contact, RTTY, FM, FT8, what ever you need to track. You can choose to differentiate between Upper Side Band and Lower Side Band, it's entirely up to you.
<p>
The next column you'll need is a callsign column, one for the other station. If you have several callsigns, you might also want to add a column for your own callsign. The operator name, theirs, presumably you know who you are, a signal report sent column and a signal report received column and if you're game a comments column.
<p>
That's the bare bones of the idea.
<p>
You can expand this to include location information, both theirs and yours, perhaps you'd like to record station information, what antenna you were using, where were you, operating on battery, the power levels, etc. The sky is the limit. Log as much or as little as seems helpful.
<p>
You'll notice at this point I've not yet talked about specific software. That's because at this point you don't actually know what you care about. For some people logging the bare minimum is enough, for others, recording the whole contact or QSO is not enough and of course there is every variation in between.
<p>
Once you've become comfortable with what to log, you can start looking for specific tools, what's suitable for your Operating System, your usage patterns, etc.
<p>
I've said previously that if you're looking at logging software, make absolutely sure that it has the ability to export your data. If it cannot export, then my strong recommendation is to discard that software as a choice, because locking away your data in a flexible environment like amateur radio is a recipe for entering data manually into a new tool and you have better things to do with your life like getting on air and making noise.
<p>
Now I started off with saying that the station log is a process and so far all I've talked about is the act of logging. The next step in the process is the act of QSL-ing, that is, exchanging your contact record with the other station. There are many different ways to do it, which is food for another day, but tracking where in the process you are, sent QSL, received QSL, confirmed QSL, etc. are just some steps that you might want to track.
<p>
One of the things that a spreadsheet won't do is track progress. Unless you start writing specific reporting modules, which from an educational perspective might be interesting, tracking progress toward a DXCC, which is contacting 100 countries, Worked All States, Worked All Continents, IOTA or Islands On The Air, SOTA or Summits On The Air and many other awards, you'll get to a point where you'll want to have a report.
<p>
At that time you can import your spreadsheet into an amateur radio logging tool and generate reports from there.
<p>
Also, Contest Logging and Station Logging are very similar but not the same. A tool that is great for a station log might be a nightmare for a contest. Contests have rules and station logs don't. Clicking your mouse or entering the time manually during a contest is not a good use of your contesting time. So consider that when you're hunting around for software.
<p>
Final comment, using an online tool, a website, to track your station log is in my opinion fine as a secondary option. It can act as a backup. As an IT professional I've yet to encounter an online log that is run as a business with service level agreements, redundancies, etc. I'm not saying that they don't exist, I've just not seen them. Keeping your primary station log on a random website run by volunteers is great for a short term effort, but long term it's asking for trouble.
<p>
Before I go, remember to make backups of your log!
<p>
I'm Onno VK6FLAB
Listen:
What's in a Chirp?
Foundations of Amateur Radio
<p>
On Thursday the 3rd of July 2008 at 6 minutes to 7 at night a developer called Dan KK7DS started to scratch an itch and published the results. The next morning before breakfast Dan added more. Since then about a hundred people from around the globe have contributed to that project.
<p>
Some people made little changes, others made large contributions over many years. In all, on average, the project saw a change every 29 hours over more than a decade of contributions.
<p>
On the 16th of July, less than two weeks into the project, it got a name, CHIRP. It's been translated from US English to Spanish, French, Hungarian, Italian, Dutch, Polish, Brazilian Portuguese, Russian and the Queens English.
<p>
From the beginning of talking to a single Icom IC-92 radio, CHIRP today supports 27 different Icom radios, 36 different brands of radio, hundreds of different radios in all, with new ones being added every couple of months or so.
<p>
The software runs on anything that will run Python, that includes Windows, OS X and Linux and it does it with an extremely modest footprint and it's free, free in cost and free as in Open Source.
<p>
If you're not familiar with CHIRP and you have a radio, then it's time to get to know this tool. It makes it simple to program your radio, to configure settings and to make backups of your current channel listings. I should mention that this is not just for hand held radios, there are plenty of HF base station radios supported.
<p>
When you run CHIRP it presents you with a window where you have a spreadsheet view of the channels in your radio. You can download the channels from your radio or upload new ones. Changing a frequency is as simple as clicking on the frequency and typing a new one, with a full-human-sized keyboard, rather than the poor excuse for a dial-pad your radio has. If your radio supports it, you can supply a human readable name, configure offsets, CTCSS and tuning step size, the mode and several other properties.
<p>
If you're unsure where to get started, CHIRP even comes with a list of frequencies to get you on your way.
<p>
You can create different configurations for different types of operations. For example, if you're into SOTA, you can make a configuration file that has all the relevant SOTA frequencies, but when you head back home and want to use the local repeater network, you can build a set for that. If you visit a different state, another country, or if you want to copy your channels from one radio to another, you can with CHIRP.
<p>
If you want to get started, there's a Beginners Guide, a list of frequently asked questions and you'll find information about what cables to use, specific errors and issues you might encounter and if you're a software developer, you'll find information on how to contribute.
<p>
If you want the ability to program your radio on any computer, you can download a boot-able CD that will run CHIRP without installing it and if you need help, there's an active mailing list, going back to 2008, an up to date wiki, issue tracker and of course, you can download the source-code, if that's your fancy.
<p>
CHIRP makes all that possible because one amateur wanted to scratch an itch.
<p>
What's itchy in your life?
<p>
I'm Onno VK6FLAB
Listen:
Creativity comes with practice
Foundations of Amateur Radio
<p>
I grew up with Lego, plastic blocks that you can put together in infinite variety. My oldest Lego kit hails from 1964, kit 324: House with Garage and it's still in pretty good nick today. It's missing the tree and the car and the garage door is broken and a few blocks have vanished, but putting it together the other day reminded me of the art of building.
<p>
Today I still play with Lego. In fact after a hiatus of several decades I pulled out my old boxes and started sorting my blocks. That lead to building the House and while I was at it, I managed to reconstruct my first Lego Technic kit, 850: Forklift, bringing with it a flood of memories.
<p>
Why the Lego?
<p>
It's been my source of inspiration for many decades. It has allowed me to imagine something and then go on to build it. Over the years I've learned that this is not a universal experience. I recall one friend who was gifted a huge Lego car, but had no idea that you were allowed to modify it and I blew his mind converting his four cylinder engine into a V6.
<p>
That same eye for the possibility exists in all of us. You need to look at things in a different light.
<p>
One of my friends likes to shop online, he also loves to roam through the local hardware store and I get regular photos of things that are useful. Last night I got a photo of a square washer. Plate of steel, galvanised, hole in the middle with the caption: I've got plans.
<p>
I took one look at it and knew that I too had plans for that washer, which is why thoughtfully he bought a couple for me too - I didn't even need to ask, it was obvious to us both.
<p>
The central hole is just the right size for an SO239, so clearly the washer is just right to act as an antenna base. You could weld it to a trailer, or drill some holes for radials, hang it from a tree, make a dipole from it, the sky is the limit and for only 76 cents, what's not to like.
<p>
I've been looking, like all my amateur friends do regularly, for a pole. I have a large 12m squidpole. It's very helpful to make into a vertical antenna. Use a bit of wire and you're good to go. It's a little floppy if you want to hold anything more substantial, like a horizontal dipole or an inverted V antenna.
<p>
So, back to the pole. I'm looking in my local hardware store for poles. Of course I could go with the Pine variety, but I'm not keen on carrying a 3.6m wooden pole on the roof of my car, or for that matter, several of them, so I've been looking for other solutions. Tent-poles, pretty cost-effective, strong if you can guy them and the load is vertical, there's painters poles, which will require some testing to see if you can combine several together and make a longer contraption.
<p>
The point is, I'm not seeing a painter's pole or a tent-pole when I'm looking, I'm seeing the ability to hold something up.
<p>
In the same way as when Calvin gets his hands on a large box and converts it into a Transmogrifier, I wander the isles of various shopping outlets looking for the possibilities that something might have, rather than the label written on the outside.
<p>
Doing this is second nature, and achieving it is a matter of practice.
<p>
The best advice I can give is to walk around with 'What-if' emblazoned on your brain.
<p>
What-if I could use this as an antenna, what-if I could use this as a battery-box, what-if this fits into my car, what-if this table is big enough for a field-day, what-if.
<p>
That same what-if attitude will stand you in good stead when you experiment with antennas. Don't be afraid of failing, the more you fail, the better you learn.
<p>
What-if isn't scary, it's in-built into this hobby of amateur radio.
<p>
I'm Onno VK6FLAB
Listen:
All the power in the world and not enough battery!
Foundations of Amateur Radio
<p>
The transceiver you use to get on air and make noise needs power to operate. The traditional voltage for our amateur equipment is 13.8 Volts. Why not 12 Volts you ask. The short answer is chemistry, but let's move on, there is lots to cover.
<p>
Generally that 13.8 Volt is specified with a +/- symbol and some percentage. For my radio it's 15%, which means that if I plug it into power that's somewhere between 11.7 Volt and 15.9 Volt, I'm good to go.
<p>
Then when you look a little closer at the specification you'll see that my radio draws 22 Amp. That's a whole chunk of juice that needs to come from a power supply. Of course that means that you'll also need to deal with 22 Amp fuses, wire capable of dealing with 13.8 Volt at 22 Amp, and connectors that won't melt when you do that.
<p>
If you look closer again, you might notice that 22 Amp is when you're using the radio at maximum power, that is, 100% duty cycle and 100% power, and only during transmit, in the case of my radio, 100 Watts for HF.
<p>
So, if I'm using a digital mode, AM or FM, at 100 Watts on HF, my radio says it will draw 22 Amp at 13.8 Volts.
<p>
Those numbers aren't correct of you're using CW or SSB. A rough number to work with for CW is 40%, that means if you're doing CW for a minute, that's the equivalent of key down at a 100% for 40 seconds and key up at 0% for 60 seconds.
<p>
SSB is roughly 4 times as efficient as AM, about 25% duty cycle, but realistically it's more like 20%, since your power consumption depends on how much you're yelling into the microphone. If you take long breaths, 0% power, whistle into the microphone, 100% of SSB, or 25% of overall power.
<p>
Now all this gets even more interesting if you consider that you're not just transmitting all the time. If you're only transmitting half the time, you need to take your power consumption down another 50%, so SSB might be 10%, CW only 20% and the digital modes 50%, from the perspective of the power supply.
<p>
So you want to go portable and need batteries. Batteries don't come in 13.8 Volt versions. So 12 Volts. Get the number of amp hour and you're good to go right?
<p>
Nope.
<p>
Your battery doesn't just run at 12 Volts and then all of a sudden stop, it runs down, you've seen it in a torch or a Walkman when the tape got slower and slower. A 26 Ah battery should give you 26 Amp for an hour at 12 Volts, but if you actually do that, you'll need to buy a new battery, because you'll have destroyed the one you just exhausted.
<p>
All of this then starts a conversation about chargers, which incidentally might put out 14.4 Volts. You might turn to solar panels, which at peak power operate at something like 18 Volts, then you stumble into the world of PWM vs MPPT solar converters or charges. Then there's the joys of over and under current, battery discharge rates, continuous versus intermittent charging, different battery types, battery safety, storage, weight, out-gassing and more fun than you'll want to know about on your morning commute.
<p>
And I haven't even talked about battery isolation, HF interference from chargers and inverters, the differences between powering your radio straight from a battery or via a DC to DC converter, using 240 Volts, or if you're in the USA 120 Volts in the field, generators, compatibility with others and how much all this might cost and if you need to invest in lotto tickets to pay for this experience.
<p>
One tool I stumbled across in my travels is the Four State QRP Group website which has the W1PNS / WA0ITP / AB8XA Battery Life Estimator, which in a single web page gives you the ability to say what mode you'll be using, for how long with what battery size and how much radio draw and it'll tell you how much more battery you'll need to get the job done. Very handy for a contest that you're hoping to operate portable from a battery.
<p>
This all to say that power is a very deep rabbit hole and it will take you some time to figure out where your use pattern puts your requirements and budget.
<p>
Here be dragons.
<p>
I'm Onno VK6FLAB
Listen:
More WSPR adventures
Foundations of Amateur Radio
<p>
Previously I've spoken about the joy of making something out of not much. On that theme I've covered WSPR, the Weak Signal Propagation Reporter, a mechanism to use a modest station to report signals received, which is something any suitably interested person can participate in, no license required.
<p>
For a time I had my radio, a Yaesu FT-857D connected to a Windows XP notebook running WSJT-X, a piece of software that has the ability to set the frequency of your radio and then listen to what the radio is hearing, attempt to decode it and then report on what was heard.
<p>
The beauty of this system is that you're using your own station to report signals heard, that is, your own antenna, your own coax, your own radio. Essentially you can use it to see what can be heard from around the world at your station.
<p>
I had this running for a while, but the set-up was less than satisfactory, because I use the same radio and antenna to run weekly nets, the computer was running Windows XP and running out of disk space since WSJT-X has the option to save all the audio heard, which was clogging up my drive.
<p>
It also meant that I was required to remember that I needed to reset the volume of the radio, set the squelch just so, disconnect and more importantly reconnect the antenna when there were storms about and a few other annoyances that became just a little too much for it to be fun.
<p>
After doing this for a couple of months I just gave up and put it into the too-hard basket.
<p>
The other day I started afresh.
<p>
I started with a Raspberry Pi. It's a single board computer, about the size of a credit card, that comes in at about $30, is powered off a USB adaptor and runs Linux. Since I've been using Linux for around 20 years now, it seemed like a natural fit. I managed to obtain an RTL-SDR dongle which if you're not familiar, is essentially a USB device that you can use to listen to RF frequencies. Without going too deep, these gadgets started life as USB DVB-T and FM receivers, you know the USB dongles that you can plug into your computer to watch free-to-air TV or listen to FM radio.
<p>
Back in March of 2010 Eric Fry got curious about figuring out if he could make a Linux version for one of the dongles work by reverse engineering the communication between the dongle and the supplied Windows software. In 2012 Antti Palosaari built on that and published his findings on the linux-media mailing list. Things exploded from there.
<p>
So, an RTL-SDR dongle, connected to a Raspberry Pi, running Linux.
<p>
At this point it would be great if I could report success and show and tell everything I've learnt, but then for that to happen I would need to actually have had success and I'm not quite there yet.
<p>
I managed to decode one, count 'em, one, WSPR packet on 6m, once.
<p>
Of course I couldn't help myself and started to improve things and since then I've not heard anything.
<p>
I can tell you that there is plenty of documentation online about the subject, and I'll be adding my version of that once I've got mine up and running.
<p>
There's a few things to work on, for example, listening on 6m is all fine and well, as long as there are 6m stations within hearing that are on and transmitting. Turns out that the station that I heard once last weekend has been switched off for a week. I've just changed bands, to see if that improves things, but only time will tell. I have also been using a mechanism to change bands automatically every 15 minutes, but without any spots I'm not sure if my set-up is working or not and I've just been unlucky not to hear anything.
<p>
The challenges continue, but then I suppose that's why I'm here in the first place. I will add that a problem shared is a problem halved. I mentioned my challenge to a local amateur who sprang into action and set-up a WSPR beacon, just so I can test against it. I'll let you know how I go, or you can monitor for my spots on the WSPR website and celebrate when you see a spot with my callsign on it, because I will be, celebrating that is.
<p>
As an aside, it continues to surprise me that this hobby has its fingers in so many different pies and my chosen profession of IT Geek is just another aspect of amateur radio.
<p>
I'm Onno VK6FLAB
Listen:
Modern Tools for a Modern Hobby
Foundations of Amateur Radio
<p>
The hobby we call amateur radio is enormous. One amateur called it a thousand hobbies in one and that just about sums it up for me. Being bored inside this hobby is not an option, because there is just so much to do and see.
<p>
Yesterday I found a completely unrelated aspect to our hobby, call it the one thousand and first hobby associated with amateur radio. A friend came over and handed me the separation kit mount for my Yaesu FT-857D, it's the bit of plastic that you clip to the back of the head of the radio, so you can mount it somewhere separate from the main body of the radio.
<p>
I have one of those already, purchased from a local supplier, at the time, 8 years ago, it cost me $80, these days it's included with the radio. For my station I needed a second mount and I really didn't want to spend that much money on three cables and some plastic, so I went hunting for alternatives. One of my friends is doing some 3D printing R&D for his job and has access to a printer to do some rapid prototyping and I wondered if that might be an option.
<p>
Turns out that I'm late to the party, people have been designing and printing bits for their radios for years.
<p>
A quick hunt through the popular 3D printing libraries showed about 500 different designs for Yaesu, Elecraft, Baofeng, ICOM and Kenwood, though I should point out that Kenwood also makes food processors and other bits that seem popular in the 3D printing world, so 500 is likely a little high, but respectable nonetheless.
<p>
I looked at 8 different libraries and found that Thingiverse is by far the most popular for bits with radio brands we know and love. It occurred to me that right here is thr perfect example of how amateur radio is a hobby that just grows and grows.
<p>
If you're looking for radio mounts, stands, buttons, microphone clips, belt clips, mount adaptors, holders, cradles, plug covers, brackets, earpiece retainers, logos, callsign stands, cogs, gears, handles, caps, pins, latches, cases, tuning knobs, CW key brackets, stacking brackets, antenna adaptors, feet, desk stands, shoulder strap holders, battery compartments, you're good to go.
<p>
I should mention that you don't even need to invest in a 3D printer at this point, you can hand the design to a printing service and get your print shipped to you in the mail.
<p>
If you cannot find what you're looking for, you can fire up a 3D CAD program and get designing to make something precisely to your own specifications and based on the current tools available, you can even see what it's going to look like by the time it's rendered in the plastic and colour of your choice.
<p>
I've only mentioned radio bits, but there's nothing stopping you from printing ladder line separators, dipole centres, antenna brackets, tuner cases, project cases for your home-brew contraption, knobs and dials, buttons and connectors and other missing parts or hard to find pieces.
<p>
If you're using standard components like a Raspberry Pi or Arduino, you'll find cases ready to go for those as well, so the more you look, the more you'll find.
<p>
The point of all this is that amateur radio is a hobby that goes far beyond someone sitting behind a radio listening to beeps, pops and crackles. Manufacturing and amateur radio go hand-in-hand and have done since the very beginning, but there's no rule that says that you have to keep using traditional tools to build what you're imagining.
<p>
The sky is the limit, and based on the efforts of CAMRAS, the CA Muller Radio Astronomy Station, PI9CAM based at the Dwingeloo Radio Telescope in the Netherlands, who captured a photo of the far side of the moon using a camera linked to an amateur radio transceiver on board of the Chinese Longjiang-2 satellite, even that limit is being explored.
<p>
I'm Onno VK6FLAB
Listen:
How effective is your station?
Foundations of Amateur Radio
<p>
We tend to spend most of our energy looking at antennas and power to evaluate how well our station works. Based on a better antenna or more power, you're likely to make more contacts is the general gist of the process.
<p>
Being a QRP operator, power rarely comes into the conversation, 5 Watts is what you get, leaving antennas as the prime method of discovering how effective we can be.
<p>
Recently I received an email from Layne AE1N, pointing me at an article he wrote on the Nashua Area Radio Society website titled: It's all about the decibels - factors in enhancing station effectiveness.
<p>
The article, goes into great detail in looking at an alternative way of measuring how well you're doing and builds on the December 2013 QST article - How Much Punch Can You Get from Different Modes?
<p>
In our hobby we measure using a thing called the decibel. I've spoken about it at great length previously. The way to use it is to compare something against something else. Using the metric used in the QST article we take as a starting point a modern transceiver, using 100 Watts, CW into a half-wave dipole at 30m.
<p>
Everything we're discussing from here on in, is related to that starting point, the zero point. I should also make clear that we're talking about the ability of the receiver to decode your message, not the strength of the signal.
<p>
If you were to use the same radio and instead of using CW, used AM, you'd have a station that was 27 dB worse off. That is, your signal would effectively become harder to hear by 27 decibel. On the other hand, you if were to replace the half-wave dipole with a 4 element Yagi, your station would be just under 7 dB better off, that is, it would be easier to hear you by 7 dB.
<p>
Of course you can combine AM and the Yagi, adding the two measurements together, coming out at minus 20 dB, which means that compared to a 100 Watt transmission on CW into a half-wave dipole, the same 100 Watt transmission on AM into a 4 element Yagi would still be harder to hear by 20 dB.
<p>
If you go from CW to SSB, you'd be 17 dB worse off, or SSB is 10 dB better than AM.
<p>
Note that when I say better and worse, it's about how much your signal can be decoded at the other end, using the same receiver, antenna, etc.
<p>
The whole article includes comparisons between CW and FM, CW and RTTY and so-on. RTTY is only 4 dB worse than CW, but most transceiver manufacturers recommend that you reduce power to a quarter power, that is, 25 Watt instead of 100 Watt when using RTTY or Digital modes, so you end up losing 14 dB for that, making RTTY slightly worse than SSB if you follow the manufacturer instructions to reduce power.
<p>
This isn't all doom and gloom however. Even though CW is very effective, we can improve things in other ways. For example, using PSK31 gives you a 7 dB head start, switching from CW to JT65 or FT8 gives you 25 dB. Even if you take into account the reduction from the loss of full power, 14 dB, you still end up in front by 11 decibel, which is more than you can get from upping power from 100 Watt to 400 Watt which only gets you 6 dB.
<p>
Adding an 11 element Yagi gives you a similar improvement as changing from CW to FT8, just over 11 dB, and using 1500 Watts is only slightly better at 12 dB.
<p>
The point I'm making is that you can use this idea to figure out how to get your signal heard. More power or a bigger antenna is only part of the conversation, picking the correct mode is just as important.
<p>
Of course, the 11 dB gain you get from moving from CW to FT8, even when reducing power, is one of the main reasons that it's so popular, much easier to change mode than to build a new fancy antenna.
<p>
One more thing, what of the 5 Watts vs. 100 Watts we started with, 13 dB. That's significant, but if you were to use 5 Watts FT8 into a quarter-wave dipole, using 100% of the 5 Watts, you'll actually be 12 dB better off than the same station using 100 Watts CW.
<p>
Check out Layne's article for a reference to QST and a whole lot more. It's a very useful way of looking at how your station can be very effective, even if you're QRP.
<p>
I'm Onno VK6FLAB
Listen:
How to select a mobile operating location
Foundations of Amateur Radio
<p>
Operating your amateur radio station at home, in your shack, is one of the often discussed aspects of our hobby. Much has been said about installation, antennas, grounding and the like, but what if you want to operate mobile?
<p>
Picking a location, of all the locations available to you, can be quite the task. For some it's daunting, others find it challenging, others take to it with ease and often you find yourself overwhelmed by choice. What makes a good operating location, what should you look for and how do you do this better?
<p>
First thing to consider is that options give you choice, choice gives you uncertainty, which can lead to stress and other unpleasantness. If you're completely flummoxed as to how to select a location, visit the Summits On The Air website, or the World Wide Flora and Fauna site and see which of the qualifying locations is reachable for you.
<p>
The choice becomes much easier if you don't have a choice. Picking from a proscribed list makes it easier to start and the more you do it, the more you'll learn about what makes a good operating location and what doesn't.
<p>
Restricting your options is one path to success, but there are others.
<p>
Over the years I've poured over maps, looked at places that qualified, tried and failed, many times.
<p>
Things I look for when I am hunting for a new place to operate from include the ability for my car to get there. I live in Australia, often shade is a consideration, away from buildings and other sources of interference. I tend to go for places that have water nearby, preferably the ocean, but I also frequent lakes and rivers. If I'm operating on VHF and UHF for a local contest I might look for a high point, something that has clear line of sight to the local amateur community, in my case a high hill or the local ranges overlooking the city basin.
<p>
For one contest I needed to visit local shires and to do that I created a map showing all the shire boundaries. I then used that map to scout possible locations and took into account how to get from this shire to the next. I learnt from that exercise that the ground beneath the operating location matters, sand versus gravel, gravel versus granite, granite versus swamp. I also learnt that overhead power lines are hard to spot on a map, but avoiding them is essential to success.
<p>
Depending on how long you plan to operate for, an hour, a day, the weekend, select a location based on the time that you're there. Picking an isolated jetty where there is potential for crime in the middle of the night is probably best for day-time activations, but might need reconsideration for an overnight adventure.
<p>
Picking a local park might be possible for 24 hours, but the local ranger might not appreciate you setting up a more permanent camp.
<p>
Often planning works to your advantage. The local council might appreciate you having a chat with them before a contest and might even offer you assistance in the form of local facilities, running water, etc. Consider using the local public open space with a community hall as your base.
<p>
There's a balance to be found between preparation and turning up on the day. If the location is something that you're only visiting for an hour, you won't need to scout, unless you're planning on a particularly elusive DX contact, but setting up camp for 48 hours with tents, masts, coax and operating positions will benefit from a visit before the actual event.
<p>
Make sure that you bring along a radio that can operate on the bands that you're planning to operate on and remember to turn it on and have a listen. I can tell you that driving for 90km to scout a location and forgetting to actually turn on the radio is an experience that I cannot recommend.
<p>
There are many places to choose from. Radio considerations aside, I mentioned shade before. The environment is important. You don't want to set-up on the side of a highway with fast moving traffic, or in a location where people will come right up to your station to get to their cars. You don't want to select a large car park where others will, for inexplicable reasons, park right next to you.
<p>
Boat ramps and jetties are good, a national park is great, a beach-side car park, the top of a hill, next to a river, are the kinds of places where you'll find an operating position that will get your mobile station up and running.
<p>
Bring along stuff. Batteries, squid-poles, rope, wire, spare coax, a table, water, a chair, your logbook, a box of tools, the little things that will give you options for when something unexpected happens, like the tree you were planning to use is further away than expected, or the shade moved, or the rubbish bin on site is just a little too close for comfort. Also bring fly spray, a rain coat, some food and consider any other things that might affect your enjoyment. Essentially, build in some flexibility.
<p>
I'll leave you with this question. What operating positions have you used and how successful were they?
<p>
I'm Onno VK6FLAB
Listen:
Brand New Callsign
Foundations of Amateur Radio
<p>
Today I have a new callsign, it's exciting, special, kind of strange, to be known as something other than VK6FLAB.
<p>
It's hard to overstate how much of your identity as a radio amateur is linked to your callsign. It's a strange phenomenon to those who are not amateurs, or who have only just joined the community and are still learning to remember what callsign they have.
<p>
We think of callsigns as semi-permanent fixtures, but realistically they're far from that. In your life as an amateur you'll operate many callsigns, even if you never change your own. When you're operating the local club-station, you'll use that callsign, or when you're participating in a special event, say an activation of an island, or some remote DX station, or when you get on air to make noise in another country.
<p>
Some stations use special contesting callsigns, either for speed, or to commemorate another amateur. There are those who collect callsigns like badges, others only ever register one and keep it for the rest of their life.
<p>
There are provisions for applying for callsigns for short duty operation, sometimes as little as 24 hours, to mark a significant event or activation. For example, in 2013 we registered VI6PROF as a special callsign for the then Chief Scientist of Western Australia, Professor Lyn Beazley, who used that callsign for two hours after dinner during the annual conference held in VK6 that year.
<p>
There are callsigns registered for marking the end of Polio, VI6POLIO, 100 years of the Wireless Institute of Australia VI100WIA. VK100MARCONI commemorated the first direct wireless message from the UK to Australia. There are callsigns registered for activating an island, like VK6WDI to activate Woody Island between the 9th and the 12th of November 2012, or VK6CHI for the Cheyene Island activation in 2007.
<p>
Special callsigns are a global phenomenon. The Straight Key Century Club operates K3Y. K1A gets used by amateurs throughout the USA for many different events, from Boy Scout camps through to the America Recycles Day, from the Georgia QSO party to the ARRL Field Day. The 2012 Olympic Games in the United Kingdom were celebrated with 2012L and 2012W callsigns. RG22RQ was for the Winter Olympic Games in Sochi.
<p>
As with anything rare, there's an active community that collects it. For special callsigns, there are amateurs who collect by trying to make contact with an elusive call, confirm their contact and receive a QSL Card to decorate their shack with.
<p>
In Australia, three times a year, on Australia Day, the 26th of January, on ANZAC Day, the 25th of April and on ITU Day, the 17th of May, a licensed amateur gets a special callsign to commemorate those special days in the calendar.
<p>
Australia Day is the official national day of Australia, marking the anniversary of the 1788 arrival of the First Fleet of British ships at Port Jackson.
<p>
ANZAC Day is the national day of remembrance in Australia and New Zealand that broadly commemorates all Australians and New Zealanders who served and died in all wars conflicts and peacekeeping operations. It's marked on the anniversary of the ANZAC landing at Gallipoli in 1915.
<p>
ITU Day is the World Telecommunication and Information Society Day, commemorating the foundation of the International Telecommunications Union on the 17th of May, 1865.
<p>
On each of these three dates, radio amateurs in Australia can replace their VK prefix with AX and use their special new callsign on-air to make contact anywhere around the world.
<p>
So, for now, I'm Onno AX6FLAB
Listen:
The reported death of Amateur Radio due to FT8 is an exaggeration
Foundations of Amateur Radio
<p>
In 2017 a new digital amateur mode called FT8 joined the ranks of inventions related to our hobby. Since then it's taken the amateur world by storm, filled the bands with contacts and attracted a strong following among radio amateurs across the planet. Making contacts with low solar cycle numbers has never been so easy.
<p>
Together with that following comes a growing chorus of those who decry this addition, the filling of our air with useless noise and it's too easy, not real radio, there's no conversation, who cares about contacts, I want to rag-chew, anyone can do this and it's not right. Clearly some think of FT8 as the end of amateur radio as we know it.
<p>
Recently I came across a list of other technologies that made amateur radio too easy and would cause the end of our hobby.
<p>
Amplitude Modulation or AM, Semi-automatic CW Keys or Bugs, Vacuum Tubes, Single Sideband or SSB, Radio Teletype or RTTY, Repeaters, Electronic CW Keyers, Transistors, Electronic digital programmable computers, Antenna Rotators, Integrated Circuits, Digital Signal Processing, Microprocessors, the Internet, CW Decoding Software, Automatic Link Establishment or ALE, Packet Radio, DX Clusters, Pactor and PSK.
<p>
Of course some of those make current amateurs just shake their head, or laugh out loud. Who could imagine that AM or SSB would cause the end of the hobby, given that they replaced spark-gap transmitters, which incidentally became prohibited in 1934.
<p>
As we invent new things - the ARRL referred to FT8 as the Latest Bright Shiny Object in Amateur Radio Digital World - we learn more, have more, do more and expect more. In 1675 Isaac Newton said: If I have seen further it is by standing on the shoulders of Giants.
<p>
Every invention builds on the ones that came before it and apart from the banning of the spark-gap transmitter, each of these newfangled baubles has made it into the mainstream of our community, to the point of being ubiquitous. Can you imagine an amateur radio without AM or SSB today?
<p>
Using Clublog aggregate data as the source, with almost 30 years of records, in 2002, CW became more popular than Phone for logging contacts. This is on the back of Phone contacts reducing overall as a percentage of logs, against the increase of RTTY, PSK and other modes.
<p>
In 2017 FT8 joined the fray and both Phone and CW logged contacts reduced markedly. Interestingly RTTY continues to be used though not at the levels seen at its prime between 2005 and 2010 or so.
<p>
As an overall percentage of contacts, FT8 is by far the most popular. 2018 showed that over 40% of logged contacts were on FT8, CW remains essentially stable at 30% and Phone contacts account for 20% of overall contacts logged on Clublog.
<p>
What this shows is that amateurs go where the contacts are. When CW worked better than Phone, it became the prominent mode. While CW use stayed the same, and Phone reduced, it was because contacts were being made with PSK and RTTY and other modes.
<p>
This doesn't reflect the death of a hobby, far from it. It reflects the pragmatic nature of making contacts. You use a mode that's going to work.
<p>
When amplifiers and big antennas were the name of the game, those were the tools being used by our community, but these days, FT8 has levelled the playing field for all comers. In a world where noise is ubiquitous and large antenna farms are possible for a select few, FT8 is making it possible for people to get on air and make some noise.
<p>
No doubt some will decry that these are not real contacts and that exchanging a signal report isn't a real contact. Of course it is. It's just a different contact. Just like a CW contact isn't the same as an SSB contact and glorious AM isn't the same as FM, a contact with FT8 is like any other, it's real, between two stations using radio gear.
<p>
I should point out that the logging information I looked at comes from Clublog and that in 1990 there were 2.4 Million QSO's logged. In 2018 there were 40.4 million. In the same time CQ WW increased the number of entries by almost 200%. Interestingly, CW logs outpaced SSB logs in 2003, 2006, 2008 and 2016.
<p>
On the 31st of May 1897 Mark Twain said: The report of my death was an exaggeration. I think we can safely say that Amateur Radio isn't going anywhere and FT8 isn't killing the hobby.
<p>
I'm Onno VK6FLAB
Listen:
Fan Vertical Antenna
Foundations of Amateur Radio
<p>
One of the single most recurring topics within our community is that of antennas. Everywhere you look is a story or a photo or a website or a contact about an antenna that came into being because somebody had an idea.
<p>
Now if you've been in the ideas field for a while you'll have learnt that having the idea is often just the start of the process. After that there's planning, sourcing, building and testing. If you're lucky you'll end up with something and a story to tell. If you manage to persist you might even end up with a working antenna.
<p>
The other day I managed to have an idea that I'd not seen anywhere else. As it turns out and perhaps not unsurprisingly, I'm not the first to have this idea. Despite that, what struck me is that I'd not seen or heard of this combination of antennas before.
<p>
As you might recall, one of my earlier forays into antennas consisted of purchasing a set of mono-band antennas. I intended to use these on my car while operating mobile, but despite countless unsuccessful attempts at making them work, the project ended up being abandoned and written up as a learning experience.
<p>
That said, each of these antennas works just fine on a roof, just not on the roof of my car.
<p>
Recently I'd been reading about how much separation is needed between antennas that are resonant on different HF bands and my research unearthed the idea that while they might affect each other to some degree the overall effect appears to be not that large. Combing that with an antenna called a fan dipole, I wondered if I could do the same with some vertical antennas. As it turns out, yes you can. It's sometimes referred to as a fan vertical.
<p>
Before I get too carried away. A fan dipole is an antenna that consists of a set of dipoles that are all fed from the same feed point. Imagine three or four dipoles, each for a different band, with each centre connected to the same balun. Each of the legs are spaced apart so they're not touching. After a bit of tuning you'll end up with a combination antenna that works on each band. The beauty of this is that it takes up the same amount of space as the largest dipole and you'll only need one feed line, rather than several. You'll also only need two sky hooks, so you won't have to plant a forest before setting up your antenna farm.
<p>
For all those reasons I wondered if I could make a single feed point for all my vertical antennas and get the same benefits. At one point I got so excited that I started modelling this in cocoaNEC, an antenna modelling tool based on NEC2, but my learning curve exceeded my skill set, so I had to postpone that in order to actually do some income generation instead.
<p>
Discussion with fellow amateurs encouraged my tomfoolery, unearthed prior work and assured me that it would work and since then I've started down the procurement phase and have now got some SO239 connectors, a piece of metal and ideas to space holes evenly with a central socket to connect my coax to. I plan to solder all the connector centres together with some thick copper wire and use the metal plate to connect all the shields together.
<p>
The only fly in the ointment at this point is my unhealthy relationship with drills. You might remember that I managed to drill a hole in my hand a while back - all healed, I was incredibly lucky, a delightful scar to remind me - so if at all possible I'd like to avoid such a thing. Last time all I wanted was to make a single hole bigger, this time I've got four 16mm holes to drill.
<p>
You'll be pleased to learn, just as my partner was, that I'm now able to use a drill press and I even splurged and added a vice, so if I'm not too clumsy, I should be able to avoid stitches this time around.
<p>
What I'm hoping to achieve is a little group of vertical antennas, connected to the same coax, mounted on the metal roof of the house, all but invisible to our neighbours without needing to swap antennas in and out like I currently do and actually use those lovely mono-band antennas I purchased so long ago. I may have to experiment with radials and tuning and no doubt there's still a gap between theory and reality, but I'll let you know how I go.
<p>
My question to you is, what antenna project are you working on?
<p>
I'm Onno VK6FLAB
Listen:
Empirical evidence and the scientific method
Foundations of Amateur Radio
<p>
The hobby of amateur radio is a curious animal. It sits at the junction between empirical evidence and the scientific method. On the one hand it's all about physics, electricity, magnetism and the science behind those. On the other hand it's about trying something out and seeing what happens.
<p>
When I started in this hobby, I was all about the science. I wanted to know "Why is it so?" "What evidence is there to support that?", all the typical questions you might ask if you're coming at this from that direction.
<p>
As is often the case, the more you know, the less you know. That is, the more you understand a topic, the more you understand that you know nothing. The deeper you dig, the more variables become apparent, the deeper the hole goes, the further away from absolute you travel.
<p>
That's not to say that our hobby is unknowable or non-deterministic, far from it. It's often so complex as to defy immediate explanation using high-school physics. You'll get to a certain point with that knowledge, then from one moment to the next you'll open a door into a world where that knowledge is just not enough.
<p>
Interestingly when you look at for example the standard way of determining the length of a dipole, a fixed number divided by the frequency, that number we use, what ever the value, is an example of an empirical evidence based number and as observations go, it's not a particularly good one, which is why when you start using it you'll find all manner of exceptions, alterations, modifiers, etc.
<p>
If there was a formula for a dipole, it would not just have that fixed number and the frequency. Nor would it be a simple division, since the number of variables is likely to head to infinity by the time you actually approach something that can model the real world.
<p>
Between those two extremes, the quick-and-dirty empirical calculation and the intricate model at the scientific end lies a point of "good enough".
<p>
The point of "good enough" is where what you're calculating is likely to end up with something that works most of the time. It's not 100% accurate, nor is it trivial, but it gives you a level of confidence that the thing you're calculating is useful and reproducible in many circumstances.
<p>
I've been told by those who have told me that they know, that the fixed number divided by the frequency is on that "good enough" point, but my experience and the evidence says otherwise. Oh, that's ok, just add 5% to that number, or just cut it long, or insert some or other correction factor to account for the variation, that will give you "good enough".
<p>
Ok, I'll bite.
<p>
If that's "good enough", why are we teaching our new amateurs that this is how you create a dipole, no explanation about the variations, the effects of the environment, the material used, just: "Here's a number that you divide by the frequency and you'll have a dipole."
<p>
My point is that it's time to revisit some of the things we think are "good enough" and look for something "better".
<p>
I'm not advocating that we all need to become theoretical physicists, though for some that might be just the ticket, but I am saying that we should not just state that making a dipole, or calculating anything associated with our hobby, should be done without context.
<p>
Here's some context for the magic number 468. Ward N0AX did the research almost a decade ago. It's a fascinating read, look it up! Turns out that the first occurrence of the magic of 468 comes in the form of 438. Yes, that's correct, 438 was the first attempt at making a magic number and it was based on measurements by G. William Lang in 1926 and it was based on averaging measurements for several antennas.
<p>
In the 1929 ARRL handbook the number 468 first appeared and has been repeated ever since.
<p>
Apparently as it turns out, the more you repeat something the more it's right. To the point of being ridiculed if you dare question the validity of such a notion.
<p>
So, what is it, scientific, or empirical, or is it a little of both?
<p>
I'm Onno VK6FLAB
Listen:
QRP EME project update #1
Foundations of Amateur Radio
<p>
Over the past year and a half I've been working on a secret project. Today I'd like to share what I've been up to. To set the scene, I'm not doing this on my own, a fellow co-conspirator is Randall VK6WR who became an amateur about 20 months ago. Randall has a long association with the Engineering Development Array and the Murchison Wide Field Array, two of several radio telescopes that are built on one of the few radio quiet areas in the world and located near the future home of the Square Kilometre Array, the SKA.
<p>
One day Randall and I started talking, as you do, new amateur, new topics, interesting new fields and ideas. We hit on the idea that radio astronomy telescopes are able to receive 2m signals. This started a discussion about using a radio telescope to receive a moon-bounce signal.
<p>
So, the idea was born. Can we create a 5 Watt signal, bounce it off the moon and have it be heard by a radio telescope?
<p>
Randall and I have been working on that on and off since our first discussion.
<p>
Let me start by pointing out that we've not managed this yet, but we think it's a project worth doing, to forge cross skill exploration by various different groups. I have a strong background in IT and a few years as a radio amateur; Randall brings with him a wealth of radio astronomy engineering expertise, not to mention signal processing, communications and myriad other skills.
<p>
We started to do this on the quiet, why talk about something that hasn't happened, might never happen, could be done by someone else who'd claim the glory before we did, and so-on.
<p>
I've come to the realisation that while those things all hold true, this is a non-trivial project to achieve and anyone who puts in the work and gets there is welcome to claim the glory.
<p>
So, in the 20 months gone by, while both working full time we've done lots of things.
<p>
Let's set the parameters. When we first started, both of us were holders of an amateur foundation license. This means hand-keyed Morse, 10 Watts and band restrictions. Because I'm me, I decided that the difference between 10 Watt and 5 Watt wasn't significant enough to make or break this, so we went with 5 Watts QRP. Our license precludes the use of WSJT modes, invented by another radio astronomer, Joe K1JT, so the signal had to be something else. We settled on a manual slow Morse signal. We're using a radio telescope at one end, so it had to be on 144 MHz.
<p>
Those decisions made, our first project was to attempt to calculate if we could actually achieve this. Conventional wisdom says no, but our ongoing calculations revised several times since our original effort, show that we're right at the edge of what is possible.
<p>
We then started the process of determining if the radio telescope could actually hear moon bounce radio signals. We have a limited field of view, roughly 20 degrees around vertical, so the moon has to essentially be above the telescope. The galactic centre is a very noisy place from a radio perspective, so it has to be at least 20 degrees away from the moon. Similarly the sun, also very noisy, needs to be 20 degrees away from the moon.
<p>
That started a process of me learning Python, so I could use Astropy to create a table with observation times that match those criteria. I'm still working on that. Having been a programmer for 35 or so years, I'm not a fan.
<p>
We did some manual calculations to do some test runs and had two amateurs send a signal to the moon, which for several reasons, we were not able to detect.
<p>
Traditional Earth Moon Earth, EME, communications benefit from ground gain, something like 3 to 5 dB of gain based on the path essentially ducting across the earth, but that requires the moon to be near the horizon, so not relevant for our project, since the moon needs to be overhead. Of course, it might mean that I need to travel half-way across the globe, so I can get the gain, but that's another project for another day.
<p>
We get some effective gain from having a very stable signal. You might recall I purchased a high stability compensated crystal module, a TCXO, for my radio a while back, this project is why I did that. Another thing I purchased at the time is mechanical filters which also provide a little effective gain.
<p>
We started the process of acquiring some high gain 144 MHz Yagi antennas, but through some miscommunication with the amateur who was selling them at a really nice price, we missed out and haven't yet bit the bullet on another set.
<p>
Initially when Randall and I started this, we were working on it on our own, we tried to learn as much as we could and test the waters ourselves. We've been at it now for a while and it's become apparent that this is going to be something that is likely to involve several other amateurs. Some have already been helping, Allen, Allan, Keith, Alek, Leigh and Marcin all contributed time and material. No doubt this list will grow as the project continues.
<p>
At the moment I'm still trying to write code to create a calendar of dates that will suit the radio telescope with the restrictions we have in relation to the moon, sun and galactic centre, so we can actually prove that the telescope can hear an amateur radio signal.
<p>
We'll need to source some high gain antennas, likely more than two.
<p>
Once we've done a one-way test, that is, me sending and the radio telescope hearing, we'd like to do the same but between two QRP stations.
<p>
No doubt the road ahead is paved with spikes, potholes and road-blocks, but as adventures go, this one has been sustaining me for nearly two years and so-far it's showing no signs of abating.
<p>
I'm Onno VK6FLAB
Listen:
What are you proud of?
Foundations of Amateur Radio
<p>
Often we forget the things we've done or achieved and every now and then it seems like a solid use of time to reflect a little on what went before and what that did. Recently I asked various amateurs what they were proud of having done or achieved in the past year, their little personal victory, their thrill to keep coming back to the hobby.
<p>
For me it was the research and production behind "Is man-made noise really vertical?".
<p>
It took several weeks to research and produce and received only a handful of responses on social media or via email, even though it was downloaded and read about 10,000 times or so. For me it gives me a thrill to have spent time digging into the Who, What, Why, When, Where and How of a topic that seems steeped in myth and often remains unexplained or unexplored.
<p>
One amateur shared that they'd made their first HF contact from Perth to Romania, one had gotten their license this year after procrastinating for 30 years, another came back to the hobby after being away for a decade. There was an amateur who managed to set-up a rotatable Yagi on 6m.
<p>
There were a couple of amateurs who have each been building a repeater network, another who built a 6m Yagi antenna and pre-amplifier, another who erected their tower after 5 years, another who managed to get an article published in the national amateur radio magazine, another who set-up their G5RV and connected it to an Air Spy to make WSPR spots after only a year and a half in the hobby.
<p>
One amateur got their license upgrade and is looking forward to learning CW next year, another got their station fully set-up and returned to being an active radio amateur. There was an amateur who managed to get through a 20m SSB pile-up.
<p>
A friend told me that their achievement of the year was to listen, both to others and themselves. There was an amateur who used 10 Watts to make a contact between Massachusetts and New Zealand, one who worked the SO-50 satellite with a Baofeng radio and a rubber duck antenna. One amateur managed to work AO-92 with the same type of gear, made two contacts and even has a recording from one of them.
<p>
One amateur celebrated the arrival of their Bengali key, considering it Christmas before Christmas. One amateur who made their first contact between Texas and the Netherlands used a 20m self-built Moxon beam constructed from wire and fishing poles.
<p>
There was an amateur who got their license and is impatient to get on air, it's been a week of waiting. One person upgraded to the top license class and actually started operating. One aspiring amateur was inspired by how easy it was to get licensed and is planning for their entrance as a licensed ham in the new year, mind you, that did't stop him from listening and decoding a NOAA satellite image using an RTL dongle.
<p>
One amateur decided that he just couldn't wait for his license, studied three days and passed his test. He's now building his first radio, looking forward to making a contact.
<p>
There's an amateur who joined the ranks and is now looking forward to going for an upgrade to his license next year. One ham has been licensed for 10 months and is already having a blast, erected his first real tower and now has a VHF antenna at 60ft, that's 20m up in the air.
<p>
There's one amateur who has been learning about what a cheap RTL-SDR dongle can do with SDR# and he's saving up for an Icom 7300. He's finding it tough to balance between spending his money on high-end audio and saving for his Icom. Take it from me, the radio wins, every time!
<p>
I've only scratched the surface of the activities undertaken in the past 12 months, but it's clear that being an amateur is a positive experience for many people, getting on air and making noise, learning, having fun, trying things and exploring this wonderful hobby is ingrained in much of the community.
<p>
Before wrapping up, I'd also like to credit Will VK6UU for independently asking the same question and for the countless amateurs who responded, many of whom I wasn't able to squeeze in this time around. Perhaps I should do this more often.
<p>
What's your proudest moment in the past 12 months? Let me know.
<p>
I'm Onno VK6FLAB
Listen:
Contest Headphones and glorious HF SSB
Foundations of Amateur Radio
<p>
Recently I managed to get some quality on-air time when I participated in a contest. This isn't about contesting. Although I suppose tangentially it is. It was a most enjoyable experience shared with some friends and because we did it at a local radio club, Sunday morning had all manner of visitors joining us for a little social chat, just the ticket for breaking the monotony of calling CQ.
<p>
Normally when I do a contest I wear headphones, actually it's a headset, that is something over my ears with an attached microphone to capture my contacts without me having to use my hands or move my head towards a fixed location while I'm making the contact.
<p>
One hour in my trusty headset broke clean in half. They've been with me since 2012 so I was a little disappointed. They weren't cheap. I'm not going to tell you what brand it is, but they're very popular in the contesting community and I bought them based on those recommendations.
<p>
Given that I now had no headset I immediately went to the nearest social media outlet to ask for recommendations on what to do next and the typical responses included different brands, ways of repairing, better models, those kinds of things. Everything you'd expect from a community which has some experience in creating a headset that actually works within the context of amateur radio.
<p>
Don't get me wrong some of these suggestions were great but I don't particularly fancy spending $500 on a headset that is suited to listen to glorious HF SSB. If you're not familiar, think long distance AM radio playing music you can barely hear hosted by a DJ you can almost make out. Making a contact using HF SSB is really an exercise in deciphering really bad audio, often with lots of people on the same frequency at the same time, all vying for your attention. Making a contact, a QSO, in that kind of pile-up can be a challenge.
<p>
The contest ran for 48 hours so in my down time I had to come up with a solution since making a repair within the time available seemed unrealistic, even though I happened to have spare parts somewhere in my shack. As an emergency standby I brought along my mobile phone in-ear headphones.
<p>
They're lightweight, cheap, and they block out the audio from nearby conversations in the shack. Everything you want in a contesting headphone. I used a microphone on a boom, attached to the desk, but that wasn't ideal, moving your head, looking at the logging screen, operating the radio, from a user interface perspective, it left me wanting.
<p>
I should add that I prefer to operate a contest using Voice Operated Control, or VOX, that is, setting up your radio in such a way that you don't need to push any buttons to talk, you open your mouth and the radio automatically starts transmitting. Very helpful when you have your hands on the keyboard and the foot-pedal is just out of reach or making your leg tired because you have to hold it up so you don't accidentally key up the transmitter.
<p>
It occurred to me that I'd never seen this particular use of a headphone in the context of amateur radio. After the contest I went out to find a similarly spartan microphone. I'm still weighing up the options but I think I might have settled on the idea of pursuing headphones and microphones intended for use on a mobile phone, precisely because they are designed to deal with blocking out surrounding audio from both the earpiece and the microphone.
<p>
As I'm describing this to you it occurs to me that it doesn't even need to be wired, a simple Bluetooth audio module plugged into the radio with wireless mobile phone headsets might just be the ticket.
<p>
What has been your recipe for success in creating an environment where you can hear a HF SSB QSO in a contest environment without spending half the value of the radio?
<p>
I'm Onno VK6FLAB
Listen:
How do I get a better antenna?
Foundations of Amateur Radio
<p>
The question that new amateurs most often ask after "What radio should I buy?" is "How do I get the best antenna?".
<p>
In a household where you're the only antenna affected aficionado the question is likely more along the lines of: "Why do you need another antenna?".
<p>
The answer is pretty much the same, an antenna is fit for purpose, generally only one purpose.
<p>
Going from A to B without walking might involve a car. If it's just you, one seat is enough, if your local cricket team is coming too, you might need more seats. If the road is rough, you might need a good suspension and if it's the middle of summer in Australia, air-conditioning isn't a luxury but a necessity.
<p>
Each of those different requirements varies depending on circumstance and need. There are plenty more variables, fuel, distance, cost, and the deeper you dig, the more choices.
<p>
Antennas are no different.
<p>
While cars have an element of fashion, colour, styling etc. antennas are more utilitarian, radio amateurs rarely care about the colour of their contraption, but they do care about cost, construction and performance.
<p>
Those three variables alone would make for plenty of choice, but we've not yet talked about some other variables that come into play.
<p>
If you're a licensed amateur, picking the frequency you want to use is obvious and a major factor in the choice of antenna, but if you're not an amateur, that's not something obvious, but you have seen it before.
<p>
Without going into the physics of how and why, imagine all the antennas you've seen in your life. There's a TV antenna on the roof, the antenna on a transistor radio, an antenna on a car, the antenna on your Wi-Fi modem, a mobile phone antenna, satellite dishes, you might have seen antennas near train lines, on top of traffic lights, on a GPS and on a satellite phone. You might not be familiar with all of them, but enough to know that there is a huge range of different types of antennas. The more you look, the more variation you find.
<p>
You might think that each of those different antennas was chosen at the whim of the person spending the money, but actually, each of those antennas was chosen for a specific job. Each of those antennas works on at least one frequency, sometimes more and does so taking into account its purpose. Is the antenna for sending, or receiving, or both? Is it supposed to work regardless of where it's installed, or how high off the ground it is? Does it need to take into account interference from a particular direction? Is it meant for strong or weak signals, does it need to have a defined lifespan, deal with a particular wind strength, etc. etc.
<p>
Answering each of those questions determines the choices made to select an antenna from the infinite variety available.
<p>
As an amateur, my licence allows me to operate in six different frequency ranges or bands. Technically that means at least six different antennas, just so I can use the frequencies I'm licensed for.
<p>
Of course I'm only scratching the surface here, since I've already explained that antennas come in many different shapes and sizes, each with different characteristics and trade-offs.
<p>
So next time you wonder why so many different antennas, that's why.
<p>
If you've been wondering when I'll answer the bit about the best antenna, you should already have a clue by now, but the real answer is unsurprisingly: "That depends."
<p>
"On what?" you ask.
<p>
On which ever variables you care about and to which degree. The best antenna depends on the questions you ask. Ask better questions, get a better antenna.
<p>
I'm Onno VK6FLAB
Listen:
When does knowing more make it harder?
Foundations of Amateur Radio
<p>
The other day one of my non amateur friends asked for some help. He wants to set up a receiver for his bush fire brigade that's available via the internet so his community can listen to the communication channels when there are fires around, or when a volunteer is out of radio range but still wants to hear what's going on.
<p>
His question was about hooking up an antenna.
<p>
We started to discuss what he already had and it turns out that he has enough coaxial cable in either 50 Ohm RG58 or alternatively 75 Ohm low loss quad shielded satellite TV coax.
<p>
He's not an amateur, won't be broadcasting and just needs it to work without spending too much money.
<p>
We then started talking about antennas and he had a tuned whip and a generic scanner antenna. Turns out that the tuned whip was for 78 MHz and he needs to listen to 164 MHz, so I suggested the scanner antenna, so called broadband, but no actual specifications.
<p>
Then we talked about how it was going to be mounted to his metal roof. Tek screws to the iron, a CB mount with solder pads. That started a conversation about waterproofing and coax rot, termination and then the ground plane.
<p>
I could get my antenna analyser out, drive to his place an hour or so away, help him install and test it and then decide that we need other options. We might still decide to do that, but it will be driven by what happens at his installation.
<p>
If you're a licensed amateur with a little experience, this story will leave you with a whole lot of but, but, but.
<p>
If you're not, then you'd come away with, that's pretty reasonable, let's go.
<p>
What I find fascinating is the gap between those two.
<p>
On the one hand you've got knowledge that says this isn't ideal, who in their right mind would hook up a random antenna without the proper ground plane with an unknown feed point impedance to a 75 Ohm coax, using solder pads on the top of a roof. There's more of course, but those are the big ticket items.
<p>
On the other hand you have an antenna, coax, connectors that fit and a high likelihood of noise coming from your radio.
<p>
I'm not going to pretend that the choices we made over the phone are the final ones, or that it will even work as described, but we discussed that and the selection of parts gives us the highest chance of success, and rather than give the right answer we went with the closest we could get without spending a cent.
<p>
The gap between knowing and not knowing can be perilous, but it can also be used as a map to navigate from one to the other.
<p>
Is this going to work? Who knows, too many variables to be certain, too many unknowns.
<p>
Sometimes ignorance is bliss and sometimes knowledge is a burden. Finding the balance is a lifetime of learning.
<p>
I'm Onno VK6FLAB
Listen:
Are you an Elmer?
Foundations of Amateur Radio
<p>
In our hobby there is a term "Elmer", referring to someone who helps new amateurs find their way inside the community, locate resources, understand techniques, etc. It's part of what we might consider the folklore of amateur radio.
<p>
I started this with the intent to quickly introduce the concept of an Elmer and then spend some time talking about our own role in this adventure, but as is often the case, I was side-tracked by my own investigation.
<p>
There is a push within the community to abandon the concept of an Elmer, that it's not real that it serves no purpose and that it's a recent invention and irrelevant to our community. Finding an Elmer today appears to be hard work, seeing the wood for the trees, finding a unicorn in this social media connected world. But as it turns out, Elmers are closer than you think.
<p>
With a little searching, the person who is credited with introducing the word Elmer into the amateur radio vocabulary was Rod W9BRD. He was the author of a column "How's DX?" in QST magazine from 1947 through to 1978. In March of 1971 he wrote:
<p>
"[t]oo frequently one hears a sad story in this little nutshell: 'Oh, I almost got a ticket, too, but Elmer, W9XYZ, moved away and I kind of lost interest.' Sure, the guy could have burned through on his own, maybe, but he, like others, wound up an almost-ham. No more Elmer. We need those Elmers. All the Elmers, including the ham who took the most time and trouble to give you a push toward your license, are the birds who keep this great game young and fresh."
<p>
Rod was first licensed in 1937 as a 14 year old. He became a silent key in 2012.
<p>
On the face of it we have this idea that an Elmer is someone who helps you get your amateur license, but it started me thinking. What if Elmer wasn't a phrase, but a reference. The name Elmer is a male name from Old English, meaning "noble" and "famous". What if W9XYZ wasn't an actual callsign, but an example, given Rod was licensed as W9BRD, it would be simple to think of XYZ as a random suffix, much like I might use VK6XYZ, which happens to be a non-existent call at the moment.
<p>
What if Rod was saying: Oh, I almost got a ticket too, but Peter VK6LB, or Paul VK5PAS or Mary VK4PZ, moved away and I kind of lost interest.
<p>
Instead of using real amateurs like I just did, Rod wanted to use a generic name, someone "nobel" and "famous", with a generic callsign to not single out a particular person.
<p>
The reference to "Elmer" takes on a whole different meaning. It means anyone, you, me, the amateur at your club, anyone who can help another person become an amateur.
<p>
As it turns out, "Elmer" is all of us, it's a way to refer to anyone and everyone, it's not a specific role or purpose, it's the invitation to you to help another amateur.
<p>
This of course means that you need to step-up. You don't need to put on your Elmer cape and become a superhero, you just need to be part of the community, to ask questions, to help with discovering answers and to encourage investigation into this exciting pursuit of amateur radio.
<p>
So, are you an Elmer and if not, what are you going to do about it?
<p>
I'm Onno VK6FLAB
Listen:
When failure doesn't matter ...
Foundations of Amateur Radio
<p>
The other day I read a message from Theodore KS5I who has been around the block a couple of times. He recalls the excitement he experienced when he was first licensed in 1967, the year I was born.
<p>
He described that at the time transistors were just coming into their own and it was so wonderful to be learning about them.
<p>
The closing sentence sealed it for me:
<p>
Theodore wrote: Perhaps, its time for some of us more mature operators to release the past so our hands are free to grab hold of the future and share the enthusiasm of those who look ahead with the same hope and excitement that we had so many years ago..
<p>
It's that level of enthusiasm that our hobby needs to foster and develop. The landscape we live in is changing all the time, but new adventures are always just around the corner. They might not look like what was available 50 years ago, or last year, or even yesterday, but they too have their place in the pursuit of amateur radio.
<p>
Learning is a lifelong activity. If you stop learning, you - as Theodore eloquently puts it - just die.
<p>
Learning can be scary. Educator Eduardo Briceño talks about the learning zone and the performance zone. The learning zone is when the goal is to improve, concentrating on what we've not yet mastered and the expectation is that mistakes will happen.
<p>
The performance zone on the other hand is when we do something as best as we can. We concentrate on what we already know and try to minimise mistakes.
<p>
Amateur radio can operate in either of those zones, doing a contest and going hard can be a performance zone activity, do what we do, do it fast and avoid mistakes.
<p>
We could also see our activities as a learning zone. We try new things, some will work and some will fail. If we're doing a contest as a learning activity, what skill do you want to master? Is it handing off the QSO, taking the log, recognising a callsign, knowing the CQ zones, matching prefixes to countries and antenna directions, picking the right band, managing battery life or recognising the band conditions?
<p>
Pick one of those skills and try different things, expect mistakes and learn from them. Over time the thing you practised will be a new skill you've mastered, ready for use when you're going hell for leather in the CQ WW making contacts left right and centre to the envy of your peers.
<p>
Of course, this doesn't just apply to contesting. For me it's currently about electronics, about figuring out how stuff works and how to apply that to my shack. For you it might be something else in the myriad of options that the 1000 hobbies that amateur radio represents.
<p>
Life is about growing. Amateur radio is a journey, not a destination. Closing off your options because valves are no longer in vogue and Allstar isn't real radio is just a recipe for stagnation.
<p>
If you have a dozen minutes to spare, check out Eduardo Briceño's TED talk: How to get better at the things you care about
<p>
One final point.
<p>
If you're new to this adventure, your license still wet, then you don't know what you don't know, so you'll spend lots of time in the learning zone. Don't be afraid, it's a great place to be and a wonderful way to explore the hobby in all its variety.
<p>
I'm Onno VK6FLAB
Listen:
The Golden Age of Amateur Radio is Now
Foundations of Amateur Radio
<p>
Imagine a world where electronics are pervasive, a transceiver can be purchased for the price of two Big Macs, kits are designed and built using simple tools at home, software makes it possible to invent new methods of communication on an almost daily basis, where long distance contacts are made throughout the day using milliwatts while ionospheric propagation is at an all-time low, where national parks and peaks are being activated at an increasing rate, where new people join in every day, where it's easier and easier to obtain a license and where the word geek is held as a badge of honour.
<p>
That world is here, it's now and when Rex, KE6MT writes that we're in the midst of a golden age of amateur radio, he hits the nail on the head, or should that be fist on the key?
<p>
It's easy to notice that amateur radio is difficult, that it's big, that it's messy, that it's full of know-it-alls, but it's hard to remember that it's fun, that it's rewarding and that every day more and more people join in and enjoy this hobby. The ideals of investigation and exploration are alive and well and the urge to participate in activities, just to get out of the house and see some daylight is strong.
<p>
While you're in the midst of a revolution, it's hard to see the wood for the trees, but make no mistake, the revolution is here, today, now, and you're smack bang in the middle of it.
<p>
Today you can go online and find any number of different amateurs who share their skills and knowledge, you can find manufacturers and suppliers at the tap of a screen, find and draw schematics, order custom circuit boards at the click of a check-out button, print an enclosure in your bedroom using plans that you downloaded or designed minutes before.
<p>
With the digitisation of amateur radio comes the promise of new adventures, with adaptive modes, with encoding and decoding in new and interesting ways, with the ability to hear what your station is producing by logging into a remote receiver anywhere on the planet, by sending messages to satellites overhead and talking to people in another country using a hand-held VHF radio.
<p>
For some the loss of the valve radio is the loss of history, for others it's a sign of progress and improvement. The inventors of spark-gap transmitters were no doubt put out by the arrival of the valve when that became commonplace. Similarly, the transistor has essentially gone the way of the Dodo in the arrival of cheaply programmable integrated circuits.
<p>
Our hobby keeps getting bigger, all the time.
<p>
We didn't abandon valves or transistors, or the spark-gap for that matter, we improved on them. You can still build a spark-gap transmitter if you feel the urge, or ferret out a valve or two and build them into something wonderful, nobody is stopping you.
<p>
Today we learn Morse Code because we want to, not because we have to.
<p>
We introduce new people with new technology, new ideas, new innovations and hope that they pick up the cape to become the next superhero.
<p>
You can bemoan the death of the hobby with the solar cycle at an all time low, the entry of stupid amateurs who need to learn from their betters, the passing of the valve and the abolition of Morse Code requirements, or you can celebrate the appearance of all the new and shiny toys that arrive in our hobby every day.
<p>
The Golden Age of Amateur Radio is Now.
<p>
I'm Onno VK6FLAB
Listen:
Everything you wanted to know about amateur radio but were afraid to ask!
Foundations of Amateur Radio
<p>
There are people who ask questions and there are people who answer them. Sometimes the people who answer even know what they're talking about, but sometimes they just repeat what they've been told without any form of critical thought.
<p>
The reason I raise this is because when you're a new amateur with a shiny new license, you're like a little puppydog, going from tree to tree to have a sniff. Does this smell good, what about this, ooh, that's a nice smell, I wonder what it tastes like.
<p>
Puppydog analogies aside, as a new amateur you're filled with questions and uncertainty. You don't know what you don't know, you don't know how much you don't know, your license is still wet, so even if you know something, it might not be true.
<p>
Interestingly the more I look at this, the more I find that new amateurs, filled with questions are more likely to dig around in the fundamental understanding of things and learn something along the way.
<p>
I've been around this community for a little while now. I obtained my license in 2010. I've learnt a lot of different things about this hobby, how it works, what the mechanisms, phenomenon, etiquette, physics and so-on make amateur radio work. Most of the time I'm learning about some or other new thing. Right now I'm learning about what a Vector Network Analyser is and how it works, so I can explain it to someone else.
<p>
Foundations of Amateur Radio is about how stuff works, much like Joe Kaufman's book - What makes it go? Though I read it in Dutch when I was growing up - Hoe zit dat in elkaar? There's another series of books by David Macaulay that are my inspiration, The Way Things Work, Unbuilding, Underground and Motel of The Mysteries to name a few.
<p>
It seems that my drive to ask questions is fundamental to my existence, my uncertainty doesn't scare me off, in fact the opposite is true, it gets me asking more questions, learning more things, gaining a deeper understanding and finding out more than I ever dreamt was possible.
<p>
If you're a new amateur, I'd recommend that you attempt to keep your curiosity alive. When you're faced with a fact, question it, attempt to discover what is underlying the response.
<p>
There are amateurs who think that to ask the question, Why is the length of a dipole calculated using some random constant? - is the equivalent of heresy, lack of skill, incompetence and the source of much derision, when it's clear that even a cursory search reveals that not only is the notion incomplete, it's wrong for most, if not all, examples.
<p>
My perspective is a little different and I'll admit that for some it might be confronting.
<p>
Why is it so?, What makes it go?, How come? and Why? are all questions to live by. You might conclude that a world where there are no certain answers is a scary place, but for my money the opposite is true.
<p>
Just because you think it's simple and answerable, doesn't make it so. If you walk in with your eyes open asking questions, then you'll be much more prepared for an unexpected response.
<p>
If you've just obtained your license and you're not sure about something, ask. You might not like or understand the answers, but that is just a recipe for more questions. Don't be deterred by those who provide certainty, the more certain they are of their answer, the more you should ask.
<p>
Amateur Radio is about experimentation, it's a license to play, a license to explore, it's a license to investigate.
<p>
For me Amateur Radio is encapsulated in a quote attributed to Albert Einstein: The more I learn, the more I realise how much I don't know.
<p>
I'm Onno VK6FLAB
Listen:
Get on air and make some noise ...
Foundations of Amateur Radio
<p>
Get on air and make some noise is a phrase I use often to encourage amateurs to be active on-air and use the bands that are available to us.
<p>
One thing that's often glossed over is how to actually make that noise. It can be scary to make that first contact.
<p>
If you've got your radio installed, your antenna erected, your operating position set-up just right and you're ready to actually key your microphone, how do you do that and how do you get the attention of those around you?
<p>
First things first.
<p>
You need to establish if your radio is actually working as expected. If you're using a UHF or VHF radio, often the simplest way is to find a local repeater, key-up your radio and give your callsign. The result should be at least a carrier, a beep or a callsign in Morse-code. Some repeaters even have a voice ident, so you can hear that your action of keying the push-to-talk had an effect. If that isn't working, then there are lots of things you can troubleshoot, but that's for another day.
<p>
If you want to do the same on HF, unless you happen to be in a position that there is a repeater within propagation distance, generally only on the 6m and 10m bands, then you're essentially out of luck. There isn't a beep, or a carrier, or a voice-ident to be found. This means we have to solve the problem in a different way.
<p>
First of all, if you cannot hear any stations, the chances of someone hearing you are slim. So, the first thing to do is to check that the squelch on your radio is set to allow all signals to arrive at your speaker. Then find a band where it's noisy. When I say noisy, find one where there is lots of hiss. Generally speaking an open band, one where propagation is getting a signal to you, makes noise, lots of noise. There are exceptions to this, but for now, find the noise.
<p>
Depending on how you have your antenna set-up, you need to make sure that you're using the right antenna for the band you're using. Some antennas work on multiple bands, others only on one, it depends entirely on what you have got hanging off the end of your radio.
<p>
Once you've found the noisiest band, go hunting for beeps, as-in Morse-code beeps, or voices, or digital sounds. Find a signal, find evidence of activity. If you have multiple noisy bands, check them all.
<p>
You might recall that this is all dependent on the ionosphere, so depending on what's going on with the sun, things will change, sometimes within a minute, an hour, or weeks. Generally there is a difference between day and night and sunrise and sunset, so experiment.
<p>
Once you've found some activity, you need to find someone to talk to. If the voice you hear is weak, look for a strong one. The stronger the better. While this isn't universally true, it's a good starting experience. Every radio and antenna combination has a sweet spot on where you know that they can hear you, but you don't know yet what that sweet spot is, so trial and error is the way to go.
<p>
HF is not like the local repeater. The people on HF can be anywhere on the planet. They might be there for the first time, or for the third time that day having been on air for sixty years, it's hard to tell.
<p>
A good analogy is to think of a sport stadium with a hundred thousand people in it. There are people all around you and you're trying to make contact with one of them. You can pick their frequency, but they're likely to be talking to someone else. You might be interrupting a daily chat, a regular net, or happen upon a contest or a special event station. You don't know which one it is and sometimes you can't hear both sides of the conversation. So, before you key your microphone and make some noise, listen to what is going on.
<p>
Once you've figured out that the station you're hearing might be amenable to talking, wait for a break in the conversation, key your microphone and just say your callsign phonetically, once. If there's no break, that's a good indication that the other station doesn't want to talk to you, unless there is an endless stream of stations, in which case the going might be tough and you might be there for a while.
<p>
If the other station acknowledges your call, great, you just made contact. Confirm that you have their callsign and that they have yours, write it down with the time and frequency, then start with exchanging information, start with a signal report. In the beginning, less is more. Your first name and city is often more than enough.
<p>
All we're doing is establishing that we can talk to someone and that they can talk to us. Don't overdo it, get a feeling for what's going on.
<p>
Then do it again.
<p>
And again.
<p>
Before long you'll have some experience on how to get on air and make some noise and you can start learning about improving your skills, becoming familiar with your radio and being an active amateur.
<p>
Hopefully that wasn't so scary, and remember, every amateur had to make their first contact one day, even those who have been on-air for longer than you've been alive.
<p>
I'm Onno VK6FLAB
Listen:
Celebrate accomplishments
Foundations of Amateur Radio
<p>
Mistakes are common in all aspects of life. Sometimes they are only known to you, other times they are public knowledge and open to ridicule and lambasting. Getting on air for the first time is an accomplishment and often the initial source of mistakes, mishaps and great frustration. Once you've made it on air, the reception to this feat is often underwhelming, people around you don't appear to appreciate the amount of effort you went to in order to key your microphone and for others to be able to hear that.
<p>
If you've been in this community for a while it's easy to forget what is involved to make that first contact and to dismiss those around you who've managed to obtain their license, acquire their equipment, install and configure it just so and to actually achieve the first visible milestone in their amateur radio journey, though technically it's audible.
<p>
If you've never done this, or if you have but have delegated it to the historical backwaters of your mind, here's an outline of some steps and mistakes along the path of making your first contact.
<p>
The first question you're likely to ask is, which radio followed quickly by, from where? Then, if you're like me and many other starting amateurs, you'll have set up your radio for operation on the local 2m or 70cm repeater, you're likely to have some kind of vertical antenna with the microphone gain and squelch set just so and have your radio set for FM. I'm skipping over power, the electrical type, but that in itself can be a feat of endurance.
<p>
After hunting around for a list of relevant frequencies, you might also have set up something like CTCSS to ensure that your signal actually gets acknowledged by the repeater.
<p>
If that's not enough, you'll also have made your radio use an offset which makes it receive using one frequency and transmit using another.
<p>
There's possibly more things you've had to do to make this work and not be subjected to the ire of the local repeater troll who appears to delight in telling you off when they feel you've done something wrong, like leave the roger beep activated or some other infraction.
<p>
If you did manage to achieve all these things and actually made your first contact on the repeater, congratulations and welcome to the hobby! Take a breath, you did well.
<p>
After a while you're likely to become more familiar with your radio and start exploring the local bands. You might program another repeater into your radio and even experiment with local simplex frequencies.
<p>
Each of these activities brings a new experience and new mistakes. For example, not all repeaters use the same offset, or even an offset in the same direction. Not all repeaters have the same CTCSS requirements.
<p>
If you're using a simplex frequency, remember to turn off the squelch - don't ask me how I know - so you have a chance to actually hear the other stations, even if you are using FM as the mode.
<p>
The process of getting on air as a first time user can be daunting, with many different points of failure along the way.
<p>
Ignore the trolls, try your best and ask for help if you get stuck and celebrate your accomplishment when you manage to make a contact.
<p>
My point is that achieving all this isn't trivial and it would be helpful if that's remembered from time to time. It's easy to dismiss an achievement made by another, but much more rewarding to celebrate it.
<p>
I'm Onno VK6FLAB
Listen:
Everything you know about dipole (calculators) is wrong ...
Foundations of Amateur Radio
<p>
The other day I did an experiment. I searched for "dipole calculator" and using the first 20 results I calculated the length of a dipole suitable for 7.130 MHz. I chose the frequency for no other reason that there is a 7130 DX net every Monday, Wednesday and Friday and for the longest time I've been unable to participate due to the lack of a HF antenna in my new shack.
<p>
So here's some things I learnt from doing this experiment.
<p>
Depending on which calculator I use, the length of my dipole can vary by over a meter from longest to shortest result.
<p>
Depending on my desire to use metric or imperial measurements, my dipole will be a different length, because of course electrons move at a different speed if you're not using the metric system.
<p>
In case you're wondering, 1 inch is defined as being exactly 2.54 cm, so there's plenty of opportunity to vary that.
<p>
Speaking of standards, we all agree that the speed of light is a constant, right? Turns out that for some calculators, you can change the speed of light.
<p>
I'll skip over the notion that none of the calculators actually show what they're using as the speed of light and move on to other interesting discoveries.
<p>
Apparently you can determine the length of a dipole down to the sub-atomic length, with one calculator going down to the size of an electron to indicate how much wire you should cut from a spool.
<p>
There are forms that make doing the calculation really easy, single box to type in the frequency, so the answer must be right.
<p>
There are some that use random standard numbers, even a text book example that uses some number, but no indication where it comes from. For example, the number 486 features regularly, but so does 150 and 5905.
<p>
There are forms that provide you with several boxes, but no indication which box needs what value, so your answer may or may not indicate the number of eggs per chicken per parsec.
<p>
One dipole calculator result is actually for a vertical, so your search engine helping you might not actually give you the calculator you expect.
<p>
There are percentage correction factors. 5% seems to be a favourite number, but no indication as to what the origin of that number is.
<p>
There's a calculator that allows you to specify the feed point impedance, not sure how that works, but it's a nice feature to have when you're calculating the length of your dipole. Not.
<p>
One regular instruction is to cut long, that is, measure your wire and cut it longer than the calculator states. How much longer is left as an exercise to the reader. Should it be 1 mm longer, 1 cm longer, or should it be 1 m longer and how much should that change if the frequency changes?
<p>
Let's move on. The word ground features heavily in these calculators. The phrase "average ground" does too. No indication as to what makes an average ground, or how to go about determining what changes if your ground isn't average.
<p>
We all agree that the dipole should be half a wave-length above the ground, right?
<p>
How much is that?
<p>
The same wave length as the length of the dipole we've just calculated, or a different one?
<p>
How does the length of the dipole vary if the height varies? While we're looking at variation, how much variation is there depending on how thick the wire you're using is and what about insulation? None of those things are even mentioned in any of these calculators.
<p>
Dipole calculators, wonderful invention, shame about the implementation.
<p>
I'm Onno VK6FLAB
Listen:
Random bits of wire ...
Foundations of Amateur Radio
<p>
One topic that is longer than all other topics combined is that of antennas. Designing, planning, sourcing, building, tuning, using, you name it, all of this is regular fare in the day of a radio amateur. I've discussed the topic here regularly and no doubt I'll revisit that when the mood or necessity takes me.
<p>
One topic that is rarely discussed is that of failure.
<p>
About six months ago I moved house. I've been rebuilding my shack, doing all manner of fancy shuffling of gear and yesterday I finally got to the point of getting some HF activity happening. During that process I went through boxes and boxes of stuff, with coax, connectors, wire, nuts, bolts, heat shrink and all the other necessities of being a member of an experimental hobby like ours.
<p>
One box contained wire. You know the adage, only two types of wire required in our hobby, cheap wire or free wire with a preference for free. This box was stuffed with wire. Bits with connectors, bits wound around spools, bits in zip-loc bags with labels, bits of random length - lots of bits of random length.
<p>
There was even an abortive attempt at labelling dipoles for various bands on the outside of a couple of zip-loc bags, but no idea if the bit of wire in the bag was actually ever tested and resonant on whatever band was on the label, so who knows, they might have just been cut long waiting for another day and another set of experiments and measurements.
<p>
I needed around 50 meters of hook-up wire for my HF antenna experiment and it occurred to me when I was hunting through my box that I couldn't look at a spool and tell you how much wire there was. I did a dodgy measurement of one bit, put it on the kitchen scales and determined that another spool was heavier, so it was likely longer, but without bringing in my calculator, doing extra measurements and doing some head scratching there was no way that I was going to get to the point of knowing how much actual wire was on that spool.
<p>
In the end I made do with the dodgy piece, soldered some joins, that's a whole other adventure, involving a gas-powered soldering iron and a flame, the flame won, as well as several other breaks and fixes.
<p>
While I was in the process of putting up my new antenna experiment it occurred to me that part of the process of experimentation, even of shack maintenance should be the documentation stage.
<p>
I have bits of terminated coax, some of it 20 meters long, some longer, some shorter. How much longer, and how much shorter you ask? No idea. But wouldn't it be great if I could put my hands on a piece of kit that I needed that was the length that I expected and not 10 meters over length, or 1 meter short.
<p>
In my audio kit, I have started labelling patch leads with their functions, using key-ring tags. I don't expect that to work for plain wire, but it should be a good solution for coax. I could use cable tie labels, but past experience with those leaves the text fading on the label. I've experimented with a printed label with clear heat shrink, but for reasons best known to chemists, the clear heat shrink becomes yellow in short order leaving the label unreadable.
<p>
I've heard of people using electrical tape with colour coding, perhaps one ring for every 5 meters of length, but they seem to come undone in the dust when you go camping.
<p>
One thing I do know is that this is a recurring problem for me. This is the first time I've actually stopped to talk about it and perhaps it means that I'll get a little closer to a solution.
<p>
I'd love to hear what you do to deal with this and how you keep track of the countless different lengths of wire, coax and rope that's lying around your shack.
<p>
I'm Onno VK6FLAB
Listen:
Is man-made noise really vertical?
Foundations of Amateur Radio
<p>
One of the often repeated attributes of noise and antennas is that man-made noise is vertically polarised and that is why a vertical antenna sounds noisier than a horizontal dipole. It's an interesting thing to say, but it it true?
<p>
Let's start with what constitutes man-made noise. Cars driving past, solar panel inverters, pool pumps, high-tension power lines, garage door openers, broadband internet modems, LED lights, lawn mowers, leaf blowers, plasma televisions and so on. The more you think about this, the more noise makers you discover.
<p>
So, are these noise sources all aligned in the same way, making the same noise?
<p>
Clearly not. There is no alignment standard for installing a lamp, how to align your lawn mower, which direction to drive, what angle to point your garage door opener, so the statement that man-made noise is vertical is clearly bogus.
<p>
That doesn't mean that the rest of the statement is also wrong. A vertical antenna in an urban environment often sounds much noisier than a horizontal one, sometimes by several dB.
<p>
So what's going on?
<p>
One suggestion is that the difference lies in the antenna itself. What if both noise sources, horizontal and vertically polarised were the same, but the antenna heard them differently, how would that look?
<p>
For starters, a horizontal dipole has a higher sensitivity at a higher angle than a vertical antenna does. So anything arriving at a low angle is picked up by the vertical, but not by the horizontal dipole.
<p>
The noise that we're talking about is local, we'll get to why in just a moment. Being local, it gets to the antenna via ground wave propagation rather than via the ionosphere. I claimed that the man-made noise we're discussing is local. It's not all local, but if it's remote, it's coming via the ionosphere and we know that it arrives at whatever angle it pleases, so there is little or no difference between a vertical and a horizontal dipole from a noise perspective for signals arriving via the ionosphere.
<p>
There is another effect. Attenuation or signal loss. In this case loss of strength. Specifically noise strength. More attenuation is the same as more signal loss.
<p>
Combining ground wave propagation and attenuation brings us to another difference between a horizontal and a vertically polarised noise source. A horizontally polarised ground wave experiences more attenuation than a vertical one. This means that noise that is local travels further and is louder when it's vertical, compared to when it's horizontal, sometimes the difference is over 20 dB.
<p>
I've been talking about horizontal and vertically polarised noise, but what if the noise is coming at an angle, like the random noise makers around you? A simple way to think of it is that every angle has a horizontal and a vertical part, in much the same way as a right-angle triangle has three sides, one horizontal, one vertical and one on an angle.
<p>
Putting this all together, we have a number of different effects, all conspiring to make the vertically polarised part of noise travel further, be louder and received better by a vertical antenna, compared to the horizontally polarised part which doesn't travel as far, is softer and heard less by a horizontal dipole.
<p>
One more thing. The isolation between vertical and horizontal polarisation can be as much as 40 dB, so a horizontal dipole won't hear vertically polarised signals well if at all and vice versa.
<p>
That doesn't make the vertical antenna useless, far from it. It's great for transmitting a long distance signal, it's small, simple to set-up and if you're in a quiet area, away from noise makers, around 500m to a kilometre or so, it's just fine as an antenna. It also doesn't need to be erected half a wavelength above the ground, doesn't need any sky-hooks, is omni-directional and in common use for most local mobile communications, so don't write off the vertical, just because it sounds noisier.
<p>
All antennas are a compromise between various elements. I've said it before and I'll say it again, likely plenty more times beyond that. The perfect antenna does not exist. We can prove that, so what ever you pick, what ever you think is the most important, that's what you'll start with and select various aspects as you go.
<p>
A vertical antenna is no worse than a horizontal dipole, it's different. Just like a Yagi is different, or a discone, or any one of the infinite supplies of antenna options. Knowing what the parameters are is the first step.
<p>
Oh, and if your neighbours complain about your lawn, tell them it's because of your noise-floor.
<p>
I'm Onno VK6FLAB
Listen:
Antenna Polarisation and you
Foundations of Amateur Radio
<p>
The first time I came across the concept of antenna polarisation was a decade before I became a radio amateur. To connect to the internet while driving around Australia I became the proud owner of a portable satellite dish. Portable in the broadest sense of the word, 150 kilos with a dish that's 2.4m high, 1.8m wide, steel base, electronics, power and patience to erect and point.
<p>
The dish has a receiver and transmitter component that needs to be aligned, just so, in order to be able to have two-way communications using 5 Watts into geosynchronous orbit. The transmit and the receive are exactly 90 degrees offset from each other. One is called horizontal polarisation, the other vertical.
<p>
The first thing to observe is that if you're using the wrong polarisation, it doesn't really work well. We'll get into what is right in a moment. Depending on where you you ask, the definition of not working well can be as bad as 40 dB loss.
<p>
Just let that sink in for a moment.
<p>
If you want to punch through with more power, you'll need to bring 10 kilowatt with you for the receiving station with the opposite polarisation to hear 1 Watt.
<p>
If you're using a VHF or UHF FM radio in your car, you're likely to have a vertical antenna. The combination of a repeater on a hill and a radio in a car adds up to much more than the the two alone. The line is blurred today because repeaters are very popular and home-base stations are becoming smaller and smaller by the week, so vertical antennas for VHF and UHF at home are today just as common as they are on cars.
<p>
It wasn't always that way. In fact, in HF, it's almost never that way and if you're a fan of Tropospheric Ducting or long distance VHF, then you'll also shy away from vertical antennas.
<p>
Let me explain.
<p>
If you want to erect a HF antenna and you want it to rotate and you want it to be high enough off the ground, you'll build the simplest mast you can get away with. Imagine a HF Yagi. It's got several elements, long to short along a boom, rotator somewhere in the middle. If you mount this Yagi horizontally, your mast will be around half a wave length in height.
<p>
If you mount the same Yagi vertically, aside from the height discussion - should it be mounted higher or not - now your mast becomes another interfering element within your Yagi. The steel wires that keep your mast standing will also interfere with the Yagi elements and your elements will be closer to the ground where they can potentially cause harmful radiation.
<p>
So from a mechanical perspective, putting a Yagi on a mast vertically is not trivial.
<p>
From a radiation perspective you may theoretically get some gain, but adding an element or two will make up for any potential gain that a vertical arrangement interacting with Earth might assist with.
<p>
There's another reason. The ionosphere. It sounds like a smooth billiard ball, it's drawn as a uniform layer around the earth, but in reality, clouds and their appearance are much more likely to represent the actual surface shapes that the ionosphere presents to your radio waves.
<p>
A signal coming in one way is unlikely to come out at the other end in the same way and vice versa.
<p>
That's HF. On VHF and UHF a horizontal signal and a vertical signal when they're used with line of sight are pretty similar, but once you get beyond that, a horizontal signal will travel further, how exactly is a story for another day. If you're doing point to point VHF or UHF contesting, horizontal is the way to go.
<p>
What about a single HF vertical?
<p>
It's excellent for a portable station, it is simple to set up, works in all directions, but it means you'll be able to hear all the local man-made noise as well, so find a quiet spot near the beach if you can.
<p>
So what's the right way? Almost always horizontal, except on cars or when you're on a DXpedition on a beach sipping pina collada and getting caught in the rain.
<p>
I'm Onno VK6FLAB
Listen:
Cloud Warming in style or what is NVIS?
Foundations of Amateur Radio
<p>
The term NVIS, or Near Vertical Incidence Skywave is in my short experience as an amateur heaped with scorn and ridicule. Terms like cloud-warmer come to mind when people discuss the principles associated with NVIS, but that does happen in the context of where I live, that is, one of the most isolated cities on the planet, Perth in Western Australia.
<p>
NVIS has several advantages over other forms of HF communication, it can be done with low power, there is little or no signal fading, simple antennas work well, it has low path loss, better signal to noise ratios and if you're in a valley, you can still use it.
<p>
So what exactly is NVIS?
<p>
In the past I've talked about long distance HF communication. Your radio signal bounces off the ionosphere, bounces back to earth and so-on. Like skipping a stone on a pond, the angle at which your signal hits the ionosphere determines what happens next. In general, shallow is good, steep is bad, much like the plop you hear when you don't hit the pond just right, a radio signal can go through the ionosphere, never to be heard again.
<p>
NVIS is about hitting the ionosphere at a steep angle, in such a way that it reflects back to earth. Without going into detail, generally you can use 40m during the day and 80m at night with some variation depending on the solar cycle and whom you want to talk to.
<p>
NVIS gives you communications less than 1000 km away, plenty to talk to everyone in your city and surrounding area. In the case of an emergency that's also likely enough to get out of any emergency affected area, so plenty of excuses to set up and try for yourself.
<p>
I can start talking about angles, maximum usable frequencies and so-on, but I won't. These all relate to specific circumstances, depend on what antenna you're using, what the ground conductivity below you is and as is typical in our hobby, many other variables.
<p>
What I can say is that NVIS to NVIS station works best, so if you're going to test this with a friend, it will help if you both set up a similar station while you learn the variation associated with this kind of communications.
<p>
Now I did mention up to 1000 km, that isn't enough to leave Western Australia, Perth to the border is about 1500 km, but if you live in the Netherlands, you can get to 15 or so countries. Depending on where you are, NVIS will give you different outcomes and what I'm talking about affects each station differently.
<p>
For me, the attraction of NVIS is solid communications on 40m and 80m, something that has eluded me so far. It also allows for a low simple wire antenna, an inverted vee dipole, two bits of wire strung up on a pole, 6m in the middle 2.5m at the end will get me up and running. Perfect for a field-day, excellent for a local contest and brilliant if you're only using low power as a beginner.
<p>
Because the antenna is close to the ground, it's pretty much omni-directional. If you set-up an antenna for 40m and then cross that with an 80m antenna and feed them both from the same point, you'll have a configuration that will operate well for 24 hours without needing to move antennas in the dark.
<p>
I have no illusions that an NVIS antenna will help me make contact between Perth and Japan, but then it's not intended for that. I've spoken in the past about finding the right tool for the job. NVIS is a tool, it has a job and it's very good at doing that. It's not for everyone, all the time, but it's a tool that you as an ambitious amateur should know about.
<p>
I'm Onno VK6FLAB
Listen:
How can I talk to my friend?
Foundations of Amateur Radio
<p>
A recurring question for people who are not yet, or newly licensed is something along the lines of: I have a friend who is 400 kilometres away, can I talk to them on my hand-held 2m radio?
<p>
This particular question arrives in different forms, but generally along the lines of attempting to communicate between point A and point B at some or other distance.
<p>
The responses, on social media at least, less so on-air, are often very technical, or offer the advice to get a license, or to get a clue, or the question is ignored or dismissed. That's not helpful, or fair. The person asking the question has expressed an interest in our hobby and is looking for help.
<p>
As a basic set of answers, if you're both standing on the ground, you'll generally be able to talk about 5km using your hand-held. Stuff between you like buildings and hills will lower that distance. If you both stand on a hill, you can talk further away. As an aside, you can talk to the International Space Station with a 2m, 144 MHz hand-held because there is nothing between you and it when it's overhead, even though it's 350 km away.
<p>
If you cannot see between the two, then an intermediate radio, a repeater, can facilitate the connection. It needs to have visibility to both radios at the same time. The higher the middle point, the further the distance. For example an antenna at 350m above the ground has a so-called radio horizon of 77km and I should point out that that's actually 15% further than actual line of sight. As long as both ends are within that radius, you should be pretty much good to go.
<p>
You can theoretically string together a whole bunch of repeaters, along a road for example, but more often than not, for distances greater than line of sight you need to invoke radio frequencies that your 2m hand-held won't do. These frequencies are generally referred to as HF and is generally anything between 3 and 30 MHz. Radio transmissions on these frequencies mainly use the ionosphere to make contact possible and you can make contacts from as close as next-door, to as far as the opposite side of the world.
<p>
The ionosphere is subject to weather in much the same way as clouds and rain. The variation in the ionosphere is driven by the sun, not by wind and humidity, and it varies throughout the day as the sun rises and sets. Communication varies depending on where the sun is and several other factors well outside this explanation. As the ionosphere changes, usable frequencies change. Something that worked one moment might not the next because the ionosphere changed.
<p>
As a licensed radio amateur you have access to many different frequencies and depending on the state of the ionosphere you can change frequency as required to alter your station to suit the conditions. You can think of it as adjusting your sail depending on the wind direction, to get from A to B.
<p>
One final point. Antennas are many and varied. They are designed for specific purpose and will react differently depending on how they're designed, built, installed and used, so the variation you're stepping into is enormous.
<p>
This hobby is nothing like dialling a phone number and making a connection, it's all about the experience and the learning. If that tickles your fancy, you're already halfway to becoming an amateur. Welcome.
<p>
I'm Onno VK6FLAB
Listen:
Nothing like the standard of Morse Code ...
Foundations of Amateur Radio
<p>
Morse Code is a way of communicating with people across the globe using dits and dahs and the spaces between them to convey a message. It's no longer required to get an Amateur License, but that doesn't mean that it's not useful, in fact, far from it, Morse is still heavily used in this hobby.
<p>
I've been attempting to learn Morse code for quite some time.
<p>
To do this I was told, time and time again, over and over, ad nauseam, that Morse is an Auditory Language. I was told that the way to success was to listen before sending, to be able to decode before ever touching a key and to learn with tapes.
<p>
I also was told that if I learned it slowly, I'd run into trouble later on when I wanted to hear a beacon, which identifies itself with much faster Morse Code.
<p>
Morse is an interesting phenomenon. We describe it in words in day-to-day terminology as having dots and dashes, which is how the International Telecommunications Union, the ITU defines it, but I have been assured that I should think of it in terms of dits and dahs, because that more closely mimics the sound of the language, and from my current experience, I have to agree.
<p>
This is an audio language and it's defined in terms of how long a dit takes to transmit. A dit is one time unit. A dah is three dits. The space between a dit and a dah within one letter is one dit. The space between two letters is three dits and the space between two words is seven dits.
<p>
I'm not expecting you to learn that right here and now, just pointing out that there is a definition of how this is supposed to work.
<p>
If you make a dit last longer, everything else lasts longer, so determining how fast you're sending something is not simple to do, unless there's a standard. Of course there's a standard.
<p>
The way that the speed in Morse is defined, is by counting how many times a standard word can be sent per minute. The Paris standard uses the word PARIS, because it is precisely 50 dits in terms of timing. There's another word, CODEX, which has 60 dits, so the two Words Per Minute are different depending on which standard you use. And to make things even more interesting, some people measure with 5 dits between words where the ITU specifies 7 dits between words.
<p>
So, speed is variable, depending on who's measuring. The ITU doesn't specify which is right, but it gets better.
<p>
As I said, this is an audio language, so you need to listen to it to learn it. Over the years it's been hammered into me, don't write Morse, don't use dits and dahs, listen, listen, listen.
<p>
I did.
<p>
At 25 Words per Minute, at what ever standard that was calculated, I can now hear Morse, that is, I can detect the gaps between letters and words and I can hear the rhythm of the code. Great, so I'm done, right?
<p>
Not so fast.
<p>
While I can hear the individual letters, I still don't actually know what a G sounds like, or what makes the letter X, or an Open Parenthesis, or a Question Mark. Easy, look them up, learn the sound, done.
<p>
Morse Code is standard, right? Right? Seriously, Morse Code is standard, right?
<p>
No.
<p>
Not so much, not even a little bit. If you search the globe for Morse Code Charts so you can look up a Question Mark you'll end up with hundreds of different charts. Everyone agrees the letter A or Alpha is dit-dah, but they cannot even agree that N, November, is dah-dit. Some show the difference between an open and a close parenthesis, others use the same character.
<p>
There's charts that put dits-and-dahs inside the letters of the alphabet, but don't specify in which order the parts are heard. The Wireless Institute of Australia doesn't even appear to bother specifying, the FISTS Down Under Morse Preservation Society doesn't show a copy, the ARRL has an abomination on their website that you cannot even link to, the ACMA defines the end of transmission as a cross and then there are the special ones, survival charts and power point slides and using words to describe a symbol, so you can know that a fraction bar is a dah-dit-dit-dah-dit, but you don't actually know what it looks like.
<p>
You'll be pleased to learn that the ITU actually publishes a document, ITU-R M.1677-1, last updated in October of 2009, that specifies the International Morse Code. It goes into great detail on what characters are defined, how to start and stop transmissions, how to transmit things like percentages, what to do if you need to send a multiplication symbol, inverted commas, minutes and second signs, fractions and as a bonus it has the phrase that this document and I quote: "should be used to define the Morse code characters and their applications in the radiocommunication services". Nothing quite like a standard that should be adopted, rather than must be adopted.
<p>
The ITU also tells us that "the code needs to be updated from time-to-time to meet the needs of the radiocommunication services". The French word "arobase", which in English is pronounced "at" and looks like the letter a with a circle, used today in an email address was added to Morse Code in 2002 by the French General Committee on Terminology, quick off the mark for a symbol that appeared on a typewriter in 1889 and first used in an email address in 1971, but if you look for an Exclamation Mark, an Ampersand, a Dollar Symbol, a Semi-Colon or an Underscore, you won't find anything about it in the ITU standard.
<p>
Oh, here's a fun fact. The ITU document says: "No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU." - so apparently I can't actually tell you that a dit-dit-dit-dah-dit-dah means that this is the end of my transmission.
<p>
I'm Onno VK6FLAB
Listen:
How to start your own net ...
Foundations of Amateur Radio
<p>
In the past I've talked about a weekly net I run, called F-troop. It's intended to be a place where new and returning amateurs find their feet, have a chat, test their gear, meet new friends, ask questions and sometimes get answers. If you want to come and join in, you're welcome to and I'd love to meet you.
<p>
This net came about because I was new to the hobby and didn't find anyone running any on-air activity for people like me. I asked around and with some encouragement I decided to start an activity. Just like that.
<p>
My point is that you can do the same. You can keep looking for that elusive group of people who share your interest, or you can get on-air and start a conversation. There's no forms to complete, there's no rules about how it has to happen, no expectations about how you run your net, just have at it.
<p>
F-troop today looks nothing like it did on day one. On the first day I was on a simplex frequency and nobody could hear me. The next week I moved to a different day and to a local repeater at a different time. After doing that for a little while, we changed day and repeater again, because we kept running into other activities.
<p>
I'm mentioning this because what you start today may look nothing like what it turns into tomorrow.
<p>
Your idea might fail, or it might succeed beyond your wildest dreams. You may find new friends or find a different activity that sparks your interest. You could inspire another amateur to join the community, or encourage someone to get on air and make some noise.
<p>
All around me there are nets, not in name, but in action. There's a group of people who get together during the week at 6am or so for about half an hour to chat on the way to work. There's a group who are learning Morse, another testing FreeDV, another chatting during the morning breakfast, another in the afternoon. There's a net for the emergency communications team, one for the local repeater group and there's a locally hosted net that attracts interest from all corners of the globe. I'm sure that there are others.
<p>
I know from personal experience that you'll get callers who might not have much to say, but your presence gives them a reason to turn their radio on and participate, to get out of their house and talk to the world. They might not say much, but your being there might be a comfort.
<p>
While F-troop is semi-organised, with a website, an advertised time and location, a dedicated host and regular callers, your net doesn't need to be any of those things. It can start as a regular chat that can grow, or it can fade away if there is no interest. Your hobby, your rules.
<p>
One thing I can tell you is that hosting a net is very rewarding. I've seen amateurs start with very little to say, very unsure of themselves, grow into their license, expand their horizons, become skilled and find a new community to make their own.
<p>
You don't need permission to start a net, you just need to decide to.
<p>
I'm Onno VK6FLAB
Listen:
Getting Started ...
Foundations of Amateur Radio
<p>
Don't get me started, Let's start this thing, Where do I start, Start me up, I could go on, but I have better things to do today, like starting a podcast.
<p>
Amateur Radio is a hobby with an enourmous range of activities, interests, skills and experiences. If you're new to this hobby, you might find yourself standing at the edge of a precipous wondering what to do next. Where do I start, who do I ask, what's the first step, what if I fail and a myriad of other doubts and concerns.
<p>
Would you be surprised to learn that this same dialog happens to every Amateur, all the time?
<p>
Let's say that I'm an experienced member of the community and there is this new mode called FT8 that keeps polluting my PSK31 transmissions. I decide that it's time to see what it's all about.
<p>
Or, imagine that you've been invited to come on a hiking trek for the first time with some fellow amateurs to activate a summit.
<p>
Or, you hear about a new entity that has just been announced.
<p>
Or, you decide that you need a new radio, a new antenna, a new head-set or a new logging package.
<p>
Or, like me, you want to try again to learn Morse Code.
<p>
For every activity you ever engage in, there's that moment of doubt, of concern, of challenge. In fact I suspect that it's exactly that thrill that makes people go ahead and pursue their hobby.
<p>
That means that as a new amateur you're no different from an old amateur. You have the same level of concern and worry that others also have and you too can overcome those by just deciding to.
<p>
So, what if you're not yet a new amateur?
<p>
The first thing to note is that everybody who is an amateur today was at one point or another not yet a new amateur. For some that step happened yesterday, for others it happened over 80 years ago and for some that step lies in the future.
<p>
At this point it would be helpful if I could point out a few resources, some things to look at, to listen to, or to engage with. If you're already on-air, listening, scan around and hear other activities. If you've managed to find the community on-line, you'll likely find other resources nearby, since we amateurs like to cluster, much like any other community. You'll also find on-line radios to hear HF, websites, discussion groups, mailing lists, interest groups, associations and clubs.
<p>
If you came across this as a random event, see what brought you here and ask around. If you're stuck, ask a fellow amateur. I can introduce you to one right now. Hi, I'm Onno VK6FLAB and I'm an Amateur Radio Operator, pleased to meet you. Drop me a line and say hello, don't be shy.
<p>
Just because you're not licensed is no excuse to get started.
<p>
There are stories everywhere of those who start as shortwave listeners, or CB-ers, or come across the hobby in some other random way, like I did.
<p>
The fact that you're here, now, means you've already found the community. Welcome. Seriously, Welcome to Amateur Radio.
<p>
Now all you need to do is take another step, and then after that, another, and before you know it you're in and among other amateurs.
<p>
There are many steps inside this hobby. Which ones you choose to take and at which speed are entirely up to you. This can be as formal or informal as you like.
<p>
I'm Onno VK6FLAB
Listen:
The mysterious three phase power ...
Foundations of Amateur Radio
<p>
There are times when you realise that you've always nodded your head when a particular topic came up and after doing that for long enough, you think you know what's going on.
<p>
Turns out that, no, you didn't, but that the topic itself was interesting enough to learn from. In my case, Three Phase Power. I came upon this topic over the past month while I struggled with power interruptions, blinking lights, weirdness throughout my house. Turns out that it's been happening for a lot longer than I've lived here.
<p>
After spending some time with the local power company, which I was told was filled with people who didn't care, turns out that they do, but they're busy people. After some back and forth, some logging, some finger pointing and head-scratching, the solution to my woes was to move me from the White Phase to the Blue Phase.
<p>
I nodded and smiled and everything was well with the world.
<p>
I know that there are three phases, Red, White and Blue. If you have overhead power in your street you'll likely notice four wires strung from pole to pole. One for each phase and one for neutral.
<p>
Apparently there's a standard for which is neutral and the order, but there are too many exceptions for me to spell that all out here, so I'll move on.
<p>
So, what's with these three phases?
<p>
If you spin a magnet between two coils you have a generator. As the magnet spins, the magnetic field increases through each coil, then peaks, then reduces, and as the next magnetic pole comes along, the magnetic field reverses, increases, peaks, reduces, etc.
<p>
If that sounds familiar, it's because I've just described a sine-wave. Every revolution of the magnet is a cycle and if you cycle, say 50 times, you get 50 cycles per second, or 50 Hz. For some countries it's not 50 Hz, but 60. Same thing, just faster.
<p>
That single set of opposing coils and magnet is a single phase. If you add another set of coils, 120 degrees further along, you get the same phenomenon, completely independently from the first set of coils.
<p>
That's the second phase. Rinse and repeat for the third phase.
<p>
To get that power to the rest of the suburb, you need to run a single wire for each phase and a common neutral wire, giving you the four wires that you see on a power pole.
<p>
Theoretically you could run with more phases, but you need to run more copper into the street, so power companies stopped at three.
<p>
You can think of these as three completely independent circuits, but they all share the same neutral, so there are some subtle interactions, like if the neutral becomes disconnected, bad news happens, especially in a place like Western Australia where ground conductivity is very poor.
<p>
In a normal home you'll get fed by one of those phases, in my case I changed over from the white phase to the blue phase. This means that each phase has a different set of users in the street. Roughly a third are using each phase.
<p>
Looking at the actual voltage and current that comes through at high enough resolution and you'll begin to recognise it as an RF spectrum with harmonics, variations, interference and other artefacts that make power show up as a varying feast, rather than the rock-solid expectation of 240V, 50 Hz you see on the sticker.
<p>
Three Phase Power, now you can nod along like I did and know how it actually works.
<p>
I'm Onno VK6FLAB.
Listen:
Water and Electronics a match made in hell ...
Foundations of Amateur Radio
<p>
It's been raining around here for a while now. Not in the order of 40 days and 40 nights, but significant. Mind you, I have lived in a place where it rained every day for 57 days, but I digress.
<p>
Water, plenty of it and often in all the wrong places.
<p>
Being a radio amateur you come across water in many aspects of the hobby, sometimes it comes in handy, like lubricating your throat while you're calling CQ, or as a ground plane for an antenna, other times, not so much, like when it enters the shack and causes the black smoke to escape from your pride and joy.
<p>
As I said, I'm no stranger to rain and in my travels I've encountered plenty of it. I managed to travel around Australia for a couple of years and I took with me a two-way satellite dish with sensitive electronics attached. Living in Australia I planned for dry. This place is dry. Often very much so, but as it turns out, dry doesn't mean without humidity, storms, rain or in one case hail.
<p>
These experiences told me a little about protecting electronics from the weather.
<p>
I should add a disclaimer here, I'm not a certified weatherman, nor am I certified in waterproofing, water ingress, or any other guarantee. So, if you do as I say and it breaks, you get to keep both halves. That said, I have some thoughts on the matter and I wouldn't be me if I didn't share them.
<p>
Water is generally everywhere. It gets into everything and it's one of those silent killers. Electronics and water rarely mix, unless you submerge the electronics in mineral spirits, or if you seal your electronics in circuit board lacquer. Even then, there are few guarantees.
<p>
The best you can hope for, in my experience, is to plan for failure, hope for success.
<p>
Finding where water gets in is often the hardest part of keeping it out. Sealing off your electronics from the world in a waterproof anything will trap heat, which in turn will cause condensation, which will ultimately cause rust and destruction of your priceless electronics.
<p>
Giving your stuff time to acclimatise is a very good idea. For example, if you have a radio stored in your garage and you bring it indoors, leave it there for several hours, if not overnight. Unless you live in Alaska with an in-floor heater to prevent your engine block from freezing, your garage is cold, your home is warm, the combination causes condensation. Alternatively, if your garage is hot, and your home air-conditioned, the reverse is true and condensation will still happen.
<p>
Water has a habit of finding its way into anything, encouraged by gravity. That means that a length of coax, run into your wall will attract a stream of water along the coax, straight into the connector and into your wall, or between the core and the braid, or into your radio, or some other undesirable place. If you create a low point before the connector, like a drip-loop, a place where water would have to go up before it can do damage, you'll likely solve the issue, but don't discard the effects of wind which can cause water to go uphill.
<p>
Connectors are magnets for water. Most connections in use in amateur radio have little or no waterproof rating. There are special waterproof connectors about and you may consider using those, but alternatives like self-amalgamating or rubber tape, which you wind tightly around a connection and in doing so, stretches and glues itself together to keep the water out. These tapes are generally not stable in the ultraviolet of the sun, so you may have to wrap that sealed connector in another layer of tape, plumbing or electrical tape is one solution.
<p>
Based on the experience from national coax installations, the way to do this is with three windings of rubber tape, followed by two of plumbing tape. Think of up as towards the weather and down as away from the weather and make the windings like this:
<p>
Wind the rubber tape three times around the connector, up, then down, then up again.
<p>
Seal this from the sun with two windings of plumbing tape, down and then back up towards the weather.
<p>
For endurance, add a cable-tie to keep the tape in place when the glue eventually fails. This will ensure that water always runs away from the connector.
<p>
The way to remember this, for a positive result, there are three ups and two downs.
<p>
If you ever get your coax wet, that is, the end, be prepared to cut off a length to protect your gear. Coax rot is real and is essentially the rusting of the braid, the shield or the core and it spells bad news for your gear.
<p>
Operating portable is a whole other subject in relation to weather, but the same principles apply. Keep the temperature stable, keep the water out, protect from rain ingress along the coax and you'll likely be able to have a good time and come home without any damage to your gear.
<p>
There is a persistent idea that rice can help you dry electronics. While it does have some effect, it's slow and by the time it's removed the water, the damage will already have been done. Air drying is much more effective. Use a fan, keep it running and you'll have a better chance of rescuing a drowned circuit.
<p>
As for electricity and water, they don't mix, they can kill and you should know better.
<p>
I'm Onno VK6FLAB
Listen:
Heated Elements and Circuit Boards
Foundations of Amateur Radio
<p>
Recently I had a conversation with a group of amateurs, ranging in experience from newbie to salty, from purchase to build, from buy to scrounge, in other words, the whole range.
<p>
One person in the group asked about how to get started with soldering. Their first harmonic had just been granted a license and they wanted to encourage the new amateur to build something, anything. That in turn started a whole conversation about the how, where, why and what of the way of the heated element and its application to a circuit board.
<p>
In 2012, almost exactly two years after obtaining my amateur license I purchased an electronics kit. The kit was sold by my local electronics store and was intended to become a High Precision LC Meter. The electronics store packages together many of the schematics that are published in Australia's Silicon Chip Magazine and in this instance, it also came with a lovely case, build instructions and a review from someone who had built the kit, John, VK3FJBX.
<p>
The whole thing cost me $90 at the time and as far as I was concerned, that was a bargain. These days I might have considered it a little high, but the end result was an LC Meter that does what I need and works as described.
<p>
The process of building the contraption was not complex, in fact, I think the single surprise was the need to purchase a Component Leg Bending Tool, a fancy name for a $2 tapered block of plastic with little indents that you can use to bend the legs of a resistor so they match the holes of the circuit board.
<p>
As projects go, this one was a success. I bought it, I built it, I put it together, powered it up and the black smoke stayed inside the components and the meter displayed numbers that matched up with what the label on the component I was testing said.
<p>
That in an of itself is a story of success. I can point at several other kits sitting in a box, still as bags of components, never assembled, lost interest, got distracted, too hard, not viable, missing bits, whatever the excuse, gathering dust until magically one day they'll be needed for when the apocalypse is here, or the garage explodes from too much stuff and I'm forced to donate it to the world.
<p>
As my life experience increases, my hands are becoming less steady. I now have a magnifying lamp, not enough clamps and less patience for silliness, so, my kit building is at an all-time-low.
<p>
Mind you, it's not that I've stopped building or experimenting, instead I'm writing software, investigating new and exciting tools, like a random online circuit simulator I came across during the week. I did want to tell you what it's called, but it's down at the moment and I don't know if it was hugged to death by well meaning amateurs who came to visit.
<p>
Search with your tool of choice for "Electronic Circuit Simulator in the Browser" and you'll be spoilt for choice. In addition to several browser based simulators around, there are also offline applications you can download and run, even tools you can spend actual money on. All told, several options for learning how to build a circuit, how various things work together, including showing simulated oscilloscope traces, so you can see what your latest contraption actually does.
<p>
The art of building, the skill of soldering, the pursuit of design is hampered by one thing, and one thing only. Your ability to get out and start.
<p>
So, what are you waiting for?
<p>
I'm Onno VK6FLAB
Listen:
The Contesting Coin Toss for the rest of us
Foundations of Amateur Radio
<p>
If you've been part of the amateur community for a while and have heard me talk on matters of contesting, you'll know that I'm an avid contester and that for me it's better than sliced bread. Of course, I'm me and you're not.
<p>
If contesting isn't of any particular interest to you, the hobby of amateur radio is big enough for at least 999 other attractions. I talk about them regularly.
<p>
If you're on the fence, or if you're unsure, or if you are not enamoured with this whole contesting thing, then today I'd like to ask you to consider another aspect of this activity. Don't worry, I'm not going to tell you to participate in a contest.
<p>
As I said, there are many other activities within the hobby. For example, testing propagation is a recurring theme, as is testing your gear, your radio, your skill and doing all manner of other amateur things. For many of those activities having another person to test with is often a way to get a result and if you find yourself on a lonely Saturday looking for a friend to help, I have a suggestion to make. It relates to contesting, specifically those on air.
<p>
It turns out that there are radio amateurs on air almost all the time. Imagine that. Better still, when there's a contest on, there are even more radio amateurs around, all clamouring about, trying to make contacts, trolling up and down the bands, making an effort to hear new stations, calling CQ, generating signals from all over the place.
<p>
Here's the thing. There is no rule that says that you have to be participating in the contest, or even log contacts for the contest, but there is no harm in you using the airwaves for your own enjoyment.
<p>
Turns out that if you get on air during a contest, you can use that for example to do testing of all manner of things. If you've run out of things to test, you can use it to learn things, like how to use the RIT or "Receiver Incremental Tuning", something Yaesu calls the Clarifier, or the IF offset, or the noise-blanker, or the noise-filter, or the A/B VFO, or what ever it is that floats your boat.
<p>
There are people all around you, getting on-air, making noise and you can join in with the fun. You can learn about the directivity of your station, observe how propagation changes, how the different bands react depending on the time of day, the solar cycle, or magnetic flux. If you have the opportunity, you can monitor the grey-line and observe its effects on what you can hear.
<p>
You can look at a DX Cluster and see what you can hear, compared to what stations other amateurs are reporting. You can measure signal strengths, the impact of the AGC, test you battery life, your mobility, the layout of your shack and if you feel the urge, you can even log a rare station and add it to your log.
<p>
No rule anywhere says that you have to participate in a contest, but why let a good opportunity go to waste?
<p>
If you're an avid contester, you might think that I'm advocating that we fill the air with time wasters, people who shouldn't be there, people who are not worth your attention. I'm here to tell you that just because you're in a contest, doesn't mean that the rest of the world is and just because you want to make an exchange, not everyone else does.
<p>
If I find myself having a conversation mid-contest with someone with a story to tell, I can participate in the discussion, or I can change the dial and call CQ contest somewhere else.
<p>
The bands are a shared resource, for those who contest and for those who don't. The interesting thing in all this to me is that there seems to be a perception that you can only fall on one side of the coin. You're either a contester, or you're not and never the twain shall meet. That just makes no sense to me. There's an opportunity to sit on either side of the divide and harness both at the same time.
<p>
I'm Onno VK6FLAB
Listen:
Programming Repeaters ... Revisited.
Foundations of Amateur Radio
<p>
It seems that when you categorically state something, like I did recently, you get emails and feedback, almost immediately, pointing out the folly of your assertion.
<p>
Within the context of setting up your radio, an hour before you go away, I intended to convey: "One thing I can categorically state is that programming your radio manually just before your holiday is really something that you should try and avoid."
<p>
That's not what I actually said. I missed out on the "just before your holiday" in that sentence. The upshot was that I received lots of feedback, some tips and different suggestions on how to do this and do it well.
<p>
As I hinted at, you should know how to program your hand held. It's almost an essential life-skill. I generally take a copy of my manual with me, either on actual paper, you know, dead-tree variety, or as electrons as a PDF on my phone or other screen-based gadget.
<p>
That doesn't mean I like programming my radio. In fact I will be so bold as to assert that I hate manually programming any of my radios. The process is tedious, non-obvious, with a process seemingly written for ENIAC in 1946 when you toggled bits on a panel to program a computer. Yes, that's a slight exaggeration, but not by much.
<p>
Anyway, given that this is such a chore, I tend to avoid it like the plague and only in case of an emergency, do I break out the user manual and poke through 17 pages of arcane button pushing-fu, to get the job done, without hopefully clearing a memory I had programmed before.
<p>
One of the emails I received, in fact the first one, was from Andrew KF7CCC. He very kindly pointed out the error of my ways, and I agree with him. One of the points that Andrew and others have made is that a defining characteristic of being a radio amateur is that we're frequency agile. That's not something that most other radio users are familiar with. They have a list of channels to pick from and switch between them. In amateur radio we have access to a VFO, a Variable Frequency Oscillator which allows us to change frequency at will.
<p>
Of course we should all be able to change frequency as the need arises. Sitting on two different channels, pre-programmed into our radios is like being users, rather than inventors of radio, shock, horror.
<p>
Andrew also mentions a book he's written. In one of the opening paragraphs he says: "This book shouldn't exist." and goes on to explain why the "Handheld Radio Field Guide" is a book that should be made obsolete by sanity entering into the process of programming a radio. I agree with the sentiment. We really have this insane configuration where each brand does it differently, and often within a brand, each model is different. Andrew makes a series of suggestions in his book and I think it's a great starting point for discussion.
<p>
As I started with, I received lots of feedback.
<p>
One suggestion was that radios should have an on-board GPS and should automatically know, based on location, which repeaters are nearby. That in turn will create a debate about where the list of repeaters comes from. Such a system appears to exist. At least one manufacturer, Icom does such a thing, but opinions appear to differ on its effectiveness.
<p>
Another was that you should program the repeater networks into your radio, so when you head away from your home, you have access to the widest range of options.
<p>
All this talk of repeaters started a lament by some that repeaters are dead and that they are not being used. Others said the opposite and welcomed new calls regularly.
<p>
I am an IT geek. I wonder if we could create a ping of sorts where a radio transmits a broadcast request for nearby repeaters and that each in turn sends a response, collected by the radio and neatly added to the list of local repeaters. If it sounds familiar, that's because in computing we do this all the time with all manner of different gadgets like printers on our local network. In fact, your radio could just listen for repeater idents and store them. Given that a repeater identifies itself regularly, that's a way we could create a repeater map locally.
<p>
What ever your poison, as-in, choice of radio, figuring out what to use it for is part of the adventure. You should know your radio inside and out. Read your user manual once in a while, I know I do, every couple of months or so, and each time I learn something new.
<p>
"One thing I can categorically state is that programming your radio manually just before your holiday is really something that you should try and avoid."
<p>
I'm Onno VK6FLAB
Listen:
Which repeaters should I put into my hand held radio?
Foundations of Amateur Radio
<p>
A regular question from people who go on holiday is: "Which repeaters should I put into my hand held radio?"
<p>
If there was infinite amount of memory and time, the answer would be simple - All of them. If it were that simple, I wouldn't be talking about it and you wouldn't be asking the question, so given that it's not that simple, what options do you have for dealing with this question, generally an hour before you pack up your suitcase to leave on that trip to another location.
<p>
For me, my first effort was to try to find a list of repeaters for the new location. Failing that, I ventured onto the national association and downloaded their list, which I might add, was woefully out of date, but I wasn't to know that when I found it. I then fired up a copy of the cross-platform CHIRP programming software, pushed all the repeater frequencies into my radio and called it a day.
<p>
I did have the benefit of a radio that was able to group memories into separate so-called banks, which allowed me to be able to select a particular bank for each state, my own state, VK6 was, and I might add, still is, in bank 6. VK5 is in bank 5 and so-on. The advantage of this arrangement is that I can select a bank, set my radio to scan in just that bank and I can hear all the activity that's happening within range of my hand held. Pretty useful when you're on holidays in a new location.
<p>
If your country doesn't quite break-down into neat little groups like that, or if you cannot break your hand held radio memory into banks, you might have to come up with a different strategy.
<p>
You could for example, create your own equivalent banks, 100 to 199 is bank 1, 200 to 299 is bank 2, etc. Or if you have 50 states to worry about, you might allocate 101, 201, 301, 401 etc. to state number one and so on. Of course that will start an argument about which state is number one, but I'm sure you can work that out for yourself.
<p>
Another suggestion is to query the local license database, in Australia the ACMA database, and get a list of currently licensed repeaters. If that's not your style, you could download a mobile phone app, something like Repeaterbook. You can even link your mobile to your radio and have the app set up the frequencies for your location.
<p>
One suggestion I came across the other day is to do none of this and to just program in all the possible repeater pairs. There's not that many possibilities and setting your radio to scan will unearth any activity on what ever standard pair is being used at the time. This won't get you completely out of the woods, since some repeaters require a CTCSS tone of some description, but several hand held radios have the ability to decode the tone. You could get fancy with pre-programmed tones in different memories, but I'll leave that as an exercise for you to imagine.
<p>
In the end, finding amateurs in a new location is a lot like finding amateurs in your home town. They're around, you just need to find them. Visiting a local club works at home and it works just as well while you're on holiday, sometimes even more-so, since you'll be a visitor and many clubs like to be on their best behaviour for new comers.
<p>
One thing I can categorically state is that programming your radio manually is really something that you should try and avoid. Not because it's not possible and not because it's not a skill you should have, but because it's error prone and there's nothing quite as frustrating as programming in the wrong frequency without having the ability to fix it when you're in the field.
<p>
One tip. CHIRP allows you to create as many different frequency files as you like. There's nothing wrong with making one fit for purpose for this outing and having a different file for your home location, or for a specific contest or DX activity.
<p>
A final bonus tip. CHIRP generally uses the microphone and headphone sockets for most hand held radios. Setting the volume correctly is a must. If you set the volume too low, CHIRP won't work, since there won't be anything to decode.
<p>
I'm Onno VK6FLAB
Listen:
How to get the best Amateur Radio gear?
Foundations of Amateur Radio
<p>
How to get the best Amateur Radio gear?
<p>
A recurring question for new entrants to our hobby, and truth be told, some experienced ones as well, is: "What's the best hand held to buy?", or the best antenna, or the best base station, the best coax, the best mount, the best software, the best something.
<p>
There's a principle in Engineering, Good, Fast and Cheap, pick any two. You can have Good and Fast, but it won't be Cheap. You can have Fast and Cheap, but it won't be Good. You can have Good and Cheap, but it won't be Fast. The concept of Quality is balanced between these limits.
<p>
With that in mind, answering the question in search of the best is already a trade-off.
<p>
To muddy the waters further, there is an economic principle related to pricing. It goes a little like this.
<p>
If you sell an amateur radio gadget for $50, there's a group of people who will buy it. There's a group of people who would have paid more for the same thing and a group of people who can't justify $50. If you make the price higher as a manufacturer, say $75, you'll get more money from some people, but the group of people who can't justify the price will get larger, so you'll sell less gadgets. If you make the price $25, you'll sell more gadgets, but you won't capture the income from those who were prepared to pay $50 or $75.
<p>
So, as a manufacturer, you make three gadgets, one for $25, one for $50 and one for $75. They're all essentially the same, but the market will lap it up. Of course, between $25 and $50, there's a group of people who would have been happy to pay more, etc. etc. Ad-infinitum.
<p>
That's our amateur radio gadget market place today. The price points might not all be taken up by the same manufacturer, but the market price for say a hand held radio goes from somewhere around $40 to over $1200. You'll find the range completely filled with offers. As an aside, your local telco is doing the same thing, as is your mobile phone manufacturer, your internet service provider and your car manufacturer to name a few.
<p>
So, now what?
<p>
We're looking for the best gadget.
<p>
Since you're going to be the one using it, your definition of best is going to be different to my definition. I care about my hand held being waterproof, but I don't care about having a torch, a compass, a thermometer or a GPS on board. You might want to take it hiking, where I'm more likely to use it on a field-day.
<p>
This means that asking another amateur, "What's the best?", is a recipe for discussion. Some will be adamant that their selection is superior to that of another amateur, but you should now already know that this is completely subjective.
<p>
If you go down the scientific route, you might use receiver sensitivity as a metric. If that's all you care about, the choice is easy, list them all by sensitivity and pick the one that's the most sensitive, but the battery life might be abysmal, or it might not use the frequency you care about, or it might have some other extra function you are paying for, but don't care about.
<p>
We get down to picking from a list. If you're anything like me, and let's face it, we're all amateurs here, you'll get to a point of making a list of the options you have. Selecting the best antenna, the best power supply, the best base station, hand held, mobile, car, service contract, you name it, it always comes to a list.
<p>
Here's how to pick.
<p>
Is option A better than B? Yes? Remove B. Is option A better than C? No? Remove A. Is option C better than D? No? Remove D. Is C better than E?, etc, etc.
<p>
You might be concerned about the ones that you've removed. You already decided that there was a better option than the one you removed, so ignore them, they're just muddying the water.
<p>
If you want to ask another amateur what they bought and why, that's a whole field of exploration, but if you ask them what's the best gadget, that's just asking for trouble.
<p>
I'm Onno VK6FLAB
Listen:
The Power for your Radio
Foundations of Amateur Radio
<p>
A question that occurs more often than you might think is one related to powering your radio. It comes in a few different flavours, like: "I want to install a radio in my car, how do I power it?", or "I want to operate portable, what's the best way to power my radio?" or "What power-supply should I buy?" There are many more versions of this, but they all come down to the same underlying challenge. I spoke about sizing a battery a couple of years ago, but that's not the only consideration.
<p>
If you look at the power specifications of my Yaesu FT-857d, you'll see 13.8V DC +/- 15%, Negative ground, 1 Amp on Receive and 22 Amp on Transmit. Based on this I purchased two 26 Amp Hour batteries and a 45 Amp variable power supply.
<p>
My amateur license restricts me to 10 Watt and I tend to operate using 5 Watt.
<p>
On receive the actual draw, specified in the documentation at 1 Amp doesn't go above 0.5 Amp in typical use. Transmit, specified at 22 Amp doesn't go above 3.6 Amp at 5 Watts and at 10 Watts it's still only 4.5 Amp, so my 45 Amp power supply is slightly overkill, by a factor of 10. By the way, that's an FM carrier on 2m. Different modes and bands have different current draw.
<p>
I should make mention of the duty-cycle, that is the difference in time spent transmitting and receiving. A 100% duty-cycle means that you're transmitting all the time, 50% means half the time and 25% means that for every minute of transmission, you'll spend three minutes listening. There is more to the duty cycle, in brief, AM, FM and RTTY are 100% duty cycle modes, CW is a 40% mode and SSB has a duty cycle of 20%. So if you're listening half the time on SSB, your duty-cycle is only 10%.
<p>
At this point you should at least understand that what the manufacturer says on the box and what your radio actually does is entirely dependent on your use case. I have no doubt that there is a way I can operate my radio so it draws 22 Amp. I'm not quite sure how, but I'm sure it's possible.
<p>
Sizing aside, there are other things you need to consider. If you're in a car, do you wire the contraption directly to your car battery, or to a secondary battery? Should it be connected directly, or via the accessory switch? Should you get a DC to DC power supply, or some other technology? Also, not all cars are 12V, not all cars have their body as earth and the thicker the wire between the battery and the radio, the better.
<p>
My decision, given that I live in a country where distances are non-trivial, and in a state bigger than Texas, in fact Western Australia is bigger than Alaska, Texas and Minnesota combined, I decided that it would be prudent to make the power supply for my radio completely separate from my car. I have a toolbox in the boot, that's the trunk if your regulator is the FCC, which contains two 26 Amp Hour batteries. I take it out to charge and put it back when I need it.
<p>
Other solutions include second batteries with disconnect on low charge circuits, manual and automatic ones, direct connect to the main battery and variations on that theme.
<p>
In shacks I've seen batteries which are constantly charged connected to a radio and dedicated power supplies bordering on being a local sub-station to ensure that enough of the good stuff makes it into the radio and out to the antenna.
<p>
For portable operation I've seen Lithium in several different flavours, car start boost batteries, mobile phone USB batteries, remote control car batteries, and the like. If you have more than one, bring some red Velcro and use it to mark the flat battery.
<p>
One of the things you'll really only be able to learn after doing it is finding out what the noise level is that a power supply generates. A battery generally doesn't make noise, but the charger or up-converter might. Inverters are often a great source of HF noise, the cheaper the more noise, so test before you buy. Also, none of what I've said so far considers emergency preparedness, which is a whole other topic for another day.
<p>
As in any technical situation, in theory, practice and theory are the same. In practice they're not.
<p>
Be prepared to do some real world tests, see what your friends are doing and see what you can take-away from that.
<p>
My purchase of a laboratory variable 45 Amp power supply was excessive, but it's likely to outlast me. The two 26 Amp Hour sealed lead acid batteries are very heavy, but I avoid carrying them as much as I can and so far, seven years later, they still last most of the weekend during a contest. There's not a one-stop solution for power, just like there isn't one for picking a radio.
<p>
How do you power your radio?
<p>
I'm Onno VK6FLAB
Listen:
Get a Contesting Buddy
Foundations of Amateur Radio
<p>
There is a solitude about amateur radio. Sitting in your shack, listening to the bands, trying to locate an elusive station and if you're doing a contest then even that can be something that you do alone. Don't get me wrong, I like my own company as much as the next introvert, but there is much joy to be found in finding a companion.
<p>
Over the years I've participated in group activities, camping, field-days, contests, activations, antenna building, ham-fests and the like. These activities have been excellent and I highly recommend that you attempt to find a local community where you can connect with other amateurs to find common ground and explore this hobby together.
<p>
Last week I did a contest with a friend. Each on our own, but doing the same contest at the same time. The contest itself was what can only be described as a fizzer. For my 8 hours or so of operating I managed a grand total of one contact and that wasn't even with my friend.
<p>
What made the experience one to remember is that I wasn't alone in the activity. I wasn't the only one having the experience. I was able to share my single contact and know that my friend didn't fare much better, that they had been in the same boat and came out just as wet.
<p>
It's not the first time I've done a contest with a single friend. This time we did it as two stations, each under our own callsign, but previously I've participated in contests where it was just two of us that were working the same callsign, both trying our best to contribute as much as we could.
<p>
The thrill of doing this is like nothing else I've experienced and I would highly recommend that you try it.
<p>
My tips for success are that you agree on a common understanding of why you're there. If one of you is wanting to lark about and the other is serious the experience will end in tears.
<p>
One of the things I've done in the past is to agree on operator rotation. For one contest we set a hard limit of two hours per operator and between us we covered most of the 48 hours of the contest and we managed enough sleep to stay sane.
<p>
Operating two radios doesn't in my experience work very well if you're both working in the same shack. That's not to say that there is hardware that can fix that, but so-far it's been elusive at best and at least frustrating. My quest for coax-stub filter bliss continues.
<p>
Motivation is a big deal. Encouraging the other person, making them a coffee at 2am in the morning, listening in and laughing helps and makes the experience one of joy.
<p>
Learning and observation is a useful spin-off from this. I've done this with people with more, sometimes decades more, experience than I and with those who have less experience. Giving feedback, write it down, don't interrupt the contest unless it's a rule breaker, and talking about it after the fact will make both of you better operators and that's not a bad outcome by any measurement.
<p>
Back-seat driving isn't OK. If the other person is operating a pile-up, let them operate it, their ears are not yours and your interjection of a callsign you heard is likely to end up in frustration for both. That's not to say that you can't do this together, just talk about it before you start "helping".
<p>
One of the most rewarding aspects of this whole process is that you get to see another person doing what you're doing and the differences in style between the two of you is often a learning experience for both, not to mention a shared history that will continue well after the contest is finished and forgotten.
<p>
Over the years I've now managed around half-a-dozen contests with a single other person, sometimes in their shack, in a club shack, on a camp-out, or in a car mobile and I have to say that it's the most fun I've had along the way.
<p>
For all I know that kind of fun can be had in a contest station that has an operator for every band with equipment coming out of every corner, but I haven't experienced that yet, so I can't comment.
<p>
Find yourself a contesting buddy to share the highs and lows and before you know it you'll be having more fun than you've had before.
<p>
I'm Onno VK6FLAB
Listen:
Logging of a Different Kind
Foundations of Amateur Radio
<p>
We as radio amateurs log things. We log our contacts, we log our progress towards an award, we log how many different countries we've contacted, which stations we heard with WSPR, how many kilometres we managed per watt, which stations were in a net, what callsigns received a QSL card, what location we're in when we made a contact. You get the point, we log things, many things and for many different reasons.
<p>
Here's a log that I started last week.
<p>
An asset log.
<p>
You heard me, an asset log, a thing that logs what amateur radio stuff I have, when it came into my life, where it came from, what brand it is, what model, what the serial number is and if I spent money on it, how much money I spent. It shows things that I've loaned to other amateurs and it shows things that are on loan to me.
<p>
It started with a conversation about a silent key. That's what we call radio amateurs who have died. The idea of a silent key is one that reminds us that everyone is unique, that every manual Morse code transmission has a particular feel and that this is unique to every amateur. Once that particular combination of speed, tone and pacing is no longer heard, they're said to have become a silent key.
<p>
I've been an amateur for a few years now and in that time I've seen the process that happens once an amateur becomes silent play out over and over again. In my experience it's not pretty. It almost always appears to end in something akin to a feeding frenzy where the person who got in first grabs the best stuff and leaves the rest for the next person. Rinse and repeat until there's nothing of value left.
<p>
It leaves me with a bad taste in many ways. For one, the family who is left behind might not know or understand that there is a monetary value associated with what's often referred to as "grandpa's gear" and they might just be in need of some extra financial support in their time of mourning.
<p>
Another aspect, if there is no actual need for money, is that the person who's shack is being dismantled might have an idea on how they would like to see their hard work live on. They might want to donate it to a particular person, an organisation, a club, a school, or some other destination of their choosing.
<p>
All that can only work if there is a list of stuff. Having a family member construct that list is going to be a tough ask, unless you're fortunate enough to have more than one amateur in your household. Asking another amateur to make the list creates a load of work with at best guesses of age and value. The only person really qualified to make the list about your shack is you.
<p>
Last week I started the list on a spreadsheet that I'll share with my family. I'll add to it when more stuff arrives and if I feel the need, I can remove stuff that has moved on. I'm not in the position to add new amateur equipment to my shack more than a few times a year, so maintaining this list isn't going to be an onerous task and I could imagine that the list expands to include tracking which equipment went with me on a field-day, which I have to tell you is always a challenge to track.
<p>
As a bonus, the list can be used in the case of loss or theft and for insurance purposes, so it's not just for when the time comes that we become a silent key. To get started, make a list of what you can see around you and keep adding stuff. If you keep accounting records, they can be used as a source of information too.
<p>
We log lots of stuff and I think that adding an asset log is something that will add to any amateur shack and it could form the basis of a legacy that you might leave behind.
<p>
I'm Onno VK6FLAB
Listen:
The Internet of Digital Radio
Foundations of Amateur Radio
<p>
The topic of how radio evolves and embraces available technology is one that describes the hobby itself. From spark-gap through AM, SSB and FM our community picked up or invented solutions to make communication possible. When the internet came along it too became a tool ripe for picking and in 1997 a connection between a radio and the internet was made with the Internet Radio Linking Project or IRLP when Dave VE7LTD, a student at the University of British Columbia, joined the UBC Amateur Radio Society. Using a radio, some hardware and a computer, you could send audio between radios across the internet.
<p>
Since then this field has exploded with D-STAR, Echolink, DMR, AllStar, Wires, CODEC2, System Fusion and Brandmeister.
<p>
At a glance they're all the same thing, radio + internet = joy.
<p>
Looking closer there are two distinct kinds of internet radio contraptions, those where the radio is digital and those where it's not. IRLP is an example of an analogue radio connecting to hardware that does the encoding into digital and transmission across the internet. At the other end the reverse process, decoding, happens and another analogue radio is used to hear the result. This encoding and decoding is done by a piece of software called a CODEC.
<p>
If we continue for a moment down the analogue path, Echolink, AllStar and Wires do similar things. In 2002 Echolink made its way onto the scene, similar to IRLP, but it didn't need any specialised hardware, any computer running the Echolink software could be used as both a client and a server, that is, you could use it to listen to Echolink, or you could use it to connect a radio to another Echolink computer.
<p>
AllStar, which started life in 2008 went a step further by making the linking completely separate. It uses the metaphor of a telephone exchange to connect nodes together, which is not surprising if you know that it's built on top of the open source telephone switching software Asterisk.
<p>
In 2012 or so, Yaesu introduced Wires which is much like Echolink and AllStar. There are servers with rooms, not unlike chat rooms, where you connect a node to and in turn your radio.
<p>
Blurring the lines between these technologies happened when you could build a computer that spoke both IRLP and Echolink at the same time. Now you can also add AllStar to that mix.
<p>
Essentially these systems do similar things. They manage switching differently, handle DTMF differently, use a different audio CODEC and handle authentication in a variety of ways, but essentially they're ways of connecting normal hand-held radios, generally FM, to each other via the internet using intermediary computers called nodes. Before you start sending angry letters, I know, there's more to it, but I've got more to tell.
<p>
While Dave was busy in Canada inventing IRLP back in the late 1990's, in Japan the Ministry of Posts and Telecommunications funded research, administered by the Japan Amateur Radio League into the digitisation of amateur radio. In 2001 that research resulted in what we know today as D-STAR. Two years later, ICOM started developing D-STAR hardware which resulted in actual physical radios less than a year later. Today you can get D-STAR hardware from ICOM, Kenwood and FlexRadio Systems.
<p>
Unlike the other technologies where the audio was converted at a central place, in D-STAR the audio is encoded in the radio and a digital signal is sent across the airwaves. That in turn means that the software that does the encoding, the CODEC, needs to be inside the radio. Since the information is digital right from the point of transmit, you can send other information, like GPS locations and messages along with the audio.
<p>
In 2005 DMR started life as a group of companies, now up to around 40, agreeing on some standards for digital audio in much the same way as D-STAR. Mostly in use by commercial users, DMR has the ability to have two users simultaneously on-air using alternate channels by having separate time slots for each channel, alternating between the two of them. They agreed to use the same CODEC to ensure compatibility. Formal interoperability testing has been happening since 2010, but because DMR allows manufacturers to build in extra features many brands cannot actually work together on the same network.
<p>
For many years D-STAR and DMR-MARC, the DMR Motorola Amateur Radio Club World Wide Network, were the main digital radio systems around in amateur radio. That changed in 2013 when Yaesu introduced System Fusion. It too made digital audio at the radio, but it added a wrinkle by making it possible to have both analogue and digital audio on the same repeater. Depending on how the repeater is configured, analogue and digital radios can coexist and communicate with each other.
<p>
The Wires system that Yaesu rolled out was upgraded in 2016, renamed to Wires X and now also incorporates digital information to allow the linking of their System Fusion repeaters.
<p>
In 2014 at the Ham Radio Exhibition in Friedrichshafen in Germany, Artem R3ABM planned to make an alternative master server for DMR+ and DMR-MARC and the result was a German wordplay which we know today as Brandmeister. It acts as a network for digital radios in much the same way as DMR, but it's run as an open alternative to the commercially available options made by Motorola and Hytera.
<p>
The story isn't complete without mentioning one other development, CODEC2. It started in 2008 when Bruce Perens K6BP contacted Jean-Marc Valin, famous for the SPEEX audio compressor and David Rowe VK5DGR about the proprietary and patented nature of low data use voice encoders such as those in use in D-STAR, DMR and System Fusion. David had already been working in this area a decade earlier and started writing code.
<p>
In 2012 during Linux Conference Australia, Jean-Marc and David spent some time together hacking and managed to make a 25% improvement and CODEC2 was well under way. Today CODEC2 forms the basis of several projects including FreeDV in software, the SM1000 FreeDV adaptor in hardware and the roadmap for the future of open and free digital voice is bright.
<p>
I should mention that this information is specifically brief to give you an overview of the landscape and hopefully I've not made too many glaring errors, but feel free to drop me a line if you do find a problem.
<p>
Digital radio and the internet, it's not just a single mode, a whole cloud of modes, and I haven't even started with WSPR, FT8 or JT65.
<p>
I'm Onno VK6FLAB
Listen:
How to find other Amateurs on Air
Foundations of Amateur Radio
<p>
Where are all the Amateurs is a question that I am asked regularly by new entrants into our community. The journey most new amateurs go through and the one I followed starts with becoming interested, getting a license, buying a radio, setting it up and then turning on your radio. If you're lucky you are at this point surrounded by other amateurs, hopefully in a club setting, or you have a friend nearby and you're off and running.
<p>
The reality is likely that even after a successful first on-air adventure, you'll be on your own in your shack asking yourself where everyone went.
<p>
I've talked in the past about picking the right day, for example, a Wednesday is likely to have less people on air than a Saturday, but that's only part of the story.
<p>
One of the things that had never occurred to me until a while after I became an amateur is that listening is a really important way to find other amateurs.
<p>
Let's start with some things that might not have occurred to you.
<p>
Most amateurs are not in your time-zone.
<p>
There is amateur radio activity almost all the time, 24/7 on whatever the appropriate band is.
<p>
Not all bands sound the same.
<p>
What worked yesterday might not work today.
<p>
This hobby isn't exact or precise, that is, there are an infinite number of variables which each affect the experience either positively or negatively and even if you used your radio in exactly the same way with the same settings on the same band in the same location at the same time with the same antenna, the landscape around you has changed, the ionosphere is a lot like the ocean, flat and calm one day, storms and waves the next.
<p>
Those things aside, each of which could be a whole story is still only part of the story of finding other amateurs.
<p>
There is a tendency for new amateurs to think of frequencies as numbers, as parameters to add to your radio, pick 7.093 MHz, pick 21.250 MHz, or 28.500 MHz, they're just numbers, things that you pick with your radio, set-up your antenna to and listen.
<p>
That's part of the story, but there is another part.
<p>
If you think of light and you go from Infra-red through visible light through to Ultraviolet light and beyond, all you're doing is changing a number, from somewhere around 300 GHz through to 3 PHz. It's a long dial in amateur radio terms, but the difference is just a number, right?
<p>
It should be obvious that the human day-to-day experience of Infra-red and Ultraviolet are completely different. The 28.5 MHz 10m band frequency is on the same spectrum as both Infra-red and Ultraviolet but you don't expect to see these frequencies or use them in the same way.
<p>
The same is true for amateur radio bands. The 80m band, the 40m band, 15m and 10m are all different. They're in use by radio amateurs, but their experience is also completely different. Some are good for day-time communications, others for night-time, some work regardless of the solar-cycle, others need solar flux. Magnetic activity affects some bands more than others and that's just the tip of the iceberg.
<p>
If you have a hand-held radio and you're used to listening to a local 2m repeater it's likely that you've set up the squelch on your radio to hide noise and your day-to-day experience is one where there is silence when nobody is talking. You might tune to 15m and look for the same silence, only to learn later on that noise is what you're actually looking for.
<p>
The sounds that the 10m band makes is different than the 80m band, the 20m band responds differently to changing conditions to the 40m band and every different radio you use has a different feel, so what you're used to with one radio will be different on another.
<p>
All this to say that the way you find other amateurs is to listen. You'll need to get a feel for this thing, a sense of opportunity.
<p>
I've compared amateur radio to fly fishing on more than one occasion. Standing up to your arm-pits in a river tossing out a line, finding a bite will be different depending on the day, the temperature, how much you moved around and the appetite of the fish around you at the time. The more you do this, the more you get a sense of opportunity and the better your results.
<p>
Instantaneous gratification is going to be elusive, get used to it, be patient, be curious and experiment.
<p>
I'll leave you with this image.
<p>
I'm currently standing in my wardrobe, surrounded by clothes, shoes, boxes and jumpers in the middle of my home with the door closed, crammed in with my microphone stand, a laptop and a tablet in an attempt to ward off the background noise that comes from a winter storm that is currently overhead unleashing the first rain of the season in spectacular style.
<p>
Some days I fantasise that my budget could manage a recording studio or even a sound-proof booth.
<p>
I'm Onno VK6FLAB
Listen:
How does a waterfall display work?
Foundations of Amateur Radio
<p>
With computers becoming more and more ensconced within the confines of our radio shack the variety of information available is increasing regularly. The introduction of a waterfall display has dramatically simplified the process of detecting what the activity level is on a particular band.
<p>
If you've never seen a waterfall display, it's often a real-time, or nearly real-time display of radio activity. Leaving aside the mechanics of how this comes about, or how much you see, generally it's presented as a picture that changes over time.
<p>
In reality it's a very compact way of showing a lot of information.
<p>
You can think of it as a chart, showing the horizontal axis as frequency, the vertical axis as time and the colour as signal strength. So as you look from left to right you'll look at higher and higher frequencies. For example, the left side might be 7 MHz and the right side might be 7.3 MHz. Halfway along is 7.150 MHz.
<p>
Similarly, now, as in zero seconds ago is at the top of the chart and 1 minute ago is lower. Depending on how fast you've set it to update the whole screen might represent 10 seconds, 10 minutes or 10 hours of information, entirely flexible, entirely configurable, entirely arbitrary.
<p>
If you think of the colour black as having no signal strength and the colour red being maximum signal strength, then the brighter the colours, the more signal there is.
<p>
A morse code signal might turn up as a series of dits and dahs running down the screen, with the oldest one being at the bottom and the newest one at the top.
<p>
An AM signal might show up as a thick line with a bright colour, that's a high signal strength in the middle and lighter colours or low signal strength towards the edges.
<p>
Every mode has its own visual characteristic and there are even modes that allow you to read information within a waterfall display.
<p>
One of the other things you'll see in a waterfall display is strange artefacts, things like a diagonal line for example.
<p>
If you think of what a diagonal line represents as a radio signal, it's something that has a strong signal at a particular time and frequency. A moment later it's changed frequency and a moment later it's done it again. The steepness of the line is dependent on two things, the speed that the frequency changes and the speed that the waterfall is updating.
<p>
Before waterfall displays, the way you'd experience such a signal would be something that flashes up as a low to high swoop, or a high to low swoop, depending on your listening mode and the direction of the frequency change.
<p>
So what is that signal?
<p>
Well, it's likely to be something called an Ionospheric Sounder. It does what you think it does. Ping the ionosphere across multiple frequencies. The station doing this is listening for a return echo to see if the ionosphere is reflective for that particular frequency at that particular moment. The information can be used to create a map of what the ionosphere is doing right now, which in turn is used to figure out what frequency to use to make a contact.
<p>
I should also mention that there is a signal identification wiki which shows and plays various identified and unidentified radio signals, hours of fun for the family.
<p>
I'm Onno VK6FLAB
Listen:
Why do you contest?
Foundations of Amateur Radio
<p>
The other week I participated in a contest. This particular contest was on the 80m band, around 3.5 MHz. The contest itself, while worthy of a mention, the Harry Angel Memorial Sprint, runs for 106 minutes and commemorates every year of Harry's life, at the time, the oldest radio amateur in Australia.
<p>
I made two contacts. Count 'm and weep. Two.
<p>
So, you could do the thing that I might have done in a previous contest, smiled, thought, "Wow, that's not very many contacts." and got on with life. You're free to do that, but I wouldn't be talking about this today if I shared your view. In fact I'm sure that in my activities as a radio amateur I've managed to learn, and in some ways unlearn some things along the way.
<p>
In a previous contest I might have operated a club station, made contacts a plenty, added to the overall club score, added new countries and multipliers, had some good natured ribbing to go along with it and walked away with nothing to show for it on my own log.
<p>
The truth is that for many of my on-air contest activities I made contacts for other callsigns, those of fellow amateurs, clubs, special events, you name it, I made contacts.
<p>
Don't get me wrong, there's absolutely nothing wrong with that, nor was it a waste of time. I learnt loads from those experiences, but my own callsign log rarely, if ever, got an outing in such activities.
<p>
So, this contest was for me. For my callsign, using my radio, my antenna, my location, my patience and my skills. I did the contest because I wanted to, for me.
<p>
As you know, I'm a fan of operating QRP, that is, low power, so this contest I used 5 Watts, a Yaesu FT857d, a multi-tap vertical antenna, screwed onto a mount on the back of my car, parked next to a river with water to the East of me, so I could benefit from any gain that water nearby might offer me.
<p>
As an aside, I'll talk more about water and gain at some other time, because it appears that not is all as my handed-down in hush-hush terms from mentor to me, would have me believe. I don't yet know enough to point at anything, but there's more than apparently meets the eye. Watch this space.
<p>
Anyway, two contacts. Not even that far from me, about 230km South and 20km North East. Both with SSB. I heard about 20 stations, some up to 3,500km away, but they were dealing with S7 noise where I had none. That's right, no noise, S0, in the middle of the city.
<p>
In addition to a heart stopping moment when the lights came on in the car park where I had set-up, my biggest fear being noisy lights, which turned out to be unfounded, my other take-aways were that I really should bring spare batteries for my LED lamp, and that I called it an LCD lamp last week. Not sure what I was thinking.
<p>
I logged using pen and paper, in doing so I was upholding a fine tradition of radio amateurs everywhere, pen and paper is by far the most popular method of logging and with two contacts made, that's not surprising.
<p>
I'm still on the lookout for sensible logging on a phone, but so-far that's eluded me. Perhaps I should write one and sell it, become rich and famous, retire, become loved in the community, kiss babies ... who am I kidding?
<p>
Seriously though. What would the ideal phone based logging app look like to you?
<p>
As for the baby-kissing famous one, let me know when you meet them, I'll stay away.
<p>
I'm Onno VK6FLAB
Listen:
Preparation for an outing ...
Foundations of Amateur Radio
<p>
Previously I've talked about leaving your shack and setting up your station in a different location. I have my car configured as a mobile shack of sorts, that is, it's got a radio, an antenna mount and wiring to manage the location of the speaker, the head-unit and the microphone.
<p>
This weekend I'm planning to do a contest and it's been a while since I operated my radio from my car.
<p>
I've been advocating that you should do some preparation before actually going and doing your thing, so during the week at lunch time I had a look around on the map and picked a spot that I'd like to operate the contest from this weekend.
<p>
I drove to the location and pretended to set-up my station, actually, I did set it up. Tuned to the actual frequency, configured my tuner, found out that the tuning range for my antenna isn't ideal for 80m, not that this was a surprise. I'm using a so-called multi-tap antenna and the tuning range is somewhat dependent on factors such as the little metal spike that sits on top and where on my car it's mounted.
<p>
In these situations I've heard other amateurs make statements that it's obvious because it's a compromise antenna. You won't actually hear me say that, since all antennas are a compromise, but then you already knew that.
<p>
More surprising was the configuration of where I put the head-unit in my car. In the past I've used a modified mobile phone suction mount but sun and age have conspired into making that unsuitable, so I learned that I'd have to figure something out before my contest.
<p>
Another surprise was that the microphone lead, which connects to a so-called separation cable, think Ethernet cable with RJ45 and joiners which connects back to the radio, had a little broken Ethernet doohicky (it's called the locking latch), which means that while you can push the connector in place, it doesn't stay.
<p>
I also remembered that this contest was going to be in the dark, so I went looking for my LCD headlamp and it wasn't where I left it.
<p>
So, now, several days later, after making my to-fix list, I actually managed to cobble together a few spare minutes and address most of my issues. The only one remaining is where to find the Allen Key for an 80m vertical antenna that I'm also bringing, just in case.
<p>
The point of all this is that normally if you'd asked me if I was ready for my contest this weekend my immediate answer would have been: "Sure". I'm glad I followed the advise I have learned from the many mistakes I've made in the past by actually checking and because I actually went on-site I also managed to check out the local HF environment which means that come contest time I won't have a surprise that could have been managed by better preparation.
<p>
No doubt there will be more to learn, but that's for after the contest. Perhaps next week.
<p>
What do you do in preparation for an outing?
<p>
I'm Onno VK6FLAB
Listen:
SWR assumptions
Foundations of Amateur Radio
<p>
In the past I've talked about the Standing Wave Ratio, the SWR, and how it describes some of the characteristics of your antenna system. I say system because it's not just the antenna, it's the connection between your radio and the antenna as well. The coax or feed line, their length and how you've connected your antenna, all feature in the performance of the entire kit and caboodle.
<p>
As an aside, that's why measuring an antenna with an SWR meter at the bottom of the antenna, while you're bolting it to the top of your mast is likely to give you a different result when compared with the measurement performed at the radio.
<p>
During the week I was asked about how cutting an antenna changes the SWR. The question included a quote from the ARRL Single-Band Dipoles page which states:
<p>
"If you see that the SWR is getting lower as you move lower in frequency, your antenna is too long. Trim a couple of inches from each end and try again."
<p>
The person asking the question, Phil, wanted to know why he was seeing a different behaviour.
<p>
I've seen the same myself and until I had the benefit of an antenna analyser it also made little sense to me.
<p>
The reason it makes little sense becomes clear once you realise what assumptions you're working under.
<p>
When you look for antennas online, or when you buy one, often it comes with a lovely SWR graph. You'll see frequencies on the horizontal axis and SWR on the vertical axis. You'll likely see a lovely mostly horizontal line with a dip downwards at the frequency where you want to use this antenna.
<p>
The assumption you will almost automatically make, I know I did, for years, was that outside the graph the line continues on its merry way in both directions. That means that you're assuming that the SWR comes down in one place and the rest of the time it's high.
<p>
If wishing made it so.
<p>
With the benefit of an antenna analyser you can graph the whole HF spectrum, and depending on the hardware, you might even be able to see VHF and UHF or higher.
<p>
One thing you'll immediately see is that the SWR is all over the place. It's up, and down, crazy lines, across the whole spectrum. You'll find enormous highs and some very interesting lows along the way.
<p>
It's one reason why I can use an antenna intended for the 10m band on the 2m band.
<p>
When you're making an antenna, like a single-band dipole, you might find yourself in a position where your antenna SWR is going up and down like a yo-yo around the frequency where you're wanting to be. The higher the frequency, the more likely that your trimming ends you in a different dip or a different high, outside the one that you're actually looking for.
<p>
One other comment. The ARRL quote which is talking about HF dipoles states that you should remove a couple of inches from each end. Let's take that literally, two inches from each end, that's 4 inches in total. Let's call it 10cm between friends. If you're trimming a dipole for 160m, you'll change the frequency by just over 1 kHz, but if you're doing this on 6m, then the same trimming will change the frequency by nearly 1 MHz and if you use that HF recommendation for 2m, the change is almost 6 MHz, so, trimming a couple of inches as the ARRL suggests will work for some dipoles on some frequencies, but might get you completely crazy results for other frequencies.
<p>
Now you know, the SWR isn't high across everything except where you care, it's all over the place and sometimes that helps, and sometimes it doesn't.
<p>
I'm Onno VK6FLAB
Listen:
Learning on 2m FM
Foundations of Amateur Radio
<p>
Last week during F-troop something very interesting happened. If you're not familiar with F-troop, it's a weekly net for new and returning amateurs and every Saturday we welcome callers to the one hour net to discuss anything and everything amateur radio. It's been going for about seven or so years, about as long as I have been making this weekly contribution to the hobby.
<p>
Normally there's a host, often it's me, but not always, handing the microphone to the next person who then in turn hands the microphone back and the host passes it on to the next caller. This is helpful for new amateurs who then only need to remember two callsigns, their own and that of the host.
<p>
It's a safe place where people can ask questions and hopefully find an answer, make a mistake, say the wrong callsign, have their roger-beep turned on, be off frequency, all the typical things you do when you're learning or when you've dusted off an old radio after having been away from the hobby for a while.
<p>
Last week we had a surprise visitor, a special event station, VI4GAMES, operated by Reg VK2MNM who in the midst of the Commonwealth Games was having little success on HF and decided to join in on our net.
<p>
After saying hello and calling in other stations I started handing the microphone to each caller, encouraging them to make contact with VI4GAMES so they could each claim a contact, end up in the log and get a QSO card for their trouble.
<p>
Sitting on the side was hard, but at the same time it was extremely rewarding.
<p>
I witnessed stations calling a special event station for the first time in their life, dealing with strange callsigns, interruptions, distortions and delays, misheard phonetics, incorrect procedures, you name it, I heard it all.
<p>
There were some who just made the contact and moved on, handing the microphone back to the host and others who started a whole discussion about their life, their station and their joy in making the contact.
<p>
There were stations just saying their callsign without phonetics, or saying it once, or fast, stomping on the other station, all the things that happen in real life when you're trying to make a contact using HF and SSB.
<p>
Just to re-iterate, this was on 2m FM, connected via IRLP, Echolink and Allstar to repeaters across the globe, with callers in Australia, New Zealand and the United States.
<p>
It was eye-opening for me.
<p>
In the past I've attempted to make contest examples, to make DX contact simulations and tried to get people to change frequency and check back in. As serendipity would have it, this was by far the most learning I've ever seen in the 7 years of this net and I'd encourage anyone to try this at home.
<p>
Some of the direct take-away tips from this are that using phonetics on 2m FM is not stupid and sometimes it's even required.
<p>
Repeating your callsign to a new station is not a waste of airtime, since you have no insight whatsoever as to the state of their receiver. You don't know if they have a poor antenna, or if they're connected via the internet, if the link is not optimal or the volume not set correctly.
<p>
Waiting until the carrier drops on the repeater is a must for many repeaters and keying and talking at the same time is a recipe for being misunderstood. Key your microphone, wait a heartbeat and then start talking.
<p>
Leaving gaps between overs allows other players onto the field and you should see that as an opportunity, not a burden.
<p>
I'm sure there were other things that were learned on that random Saturday and who knew that you could learn that much from 2m FM, special event stations and some patience.
<p>
I'm Onno VK6FLAB
Listen:
Shakespeare and Coax Stub Filters
Foundations of Amateur Radio
<p>
If you read it on the Internet, it must be true, but what happens if you read it and there are 700 different answers?
<p>
In my day job I search countless times a day for answers to problems. Based on my experience I can look at a list of responses to a question and tell myself what the skill-set is of the poster, "they don't know what they're talking about", "they're guessing", "they've got no clue", "they tried it", "ah, this one knows what they're talking about".
<p>
As an aside, a company once advocated that we should use social media as a way to provide support to customers, but based on my experience, seeing the correct answer in a series of posts being voted down into oblivion and seeing the wrong answer being promoted is a fantastic example of why that won't work, ever. Infinite monkeys with typewriters might eventually write Shakespeare, but it will take an infinite amount of time and before they succeed there will be a whole lot of rubbish.
<p>
When I started researching magnetic loop antennas several years ago I went through the same process, search for answers online. I found lots of different stories, opinions, measurements, contradictory statements and formulas. I spent some weeks reading everything I could on the subject and after a while a picture started emerging that started to explain to me how a magnetic loop antenna works. I'm no expert, my foray into this died when two ADSL modem transformers died within seconds of me hitting the PTT on my radio and I sort of lost interest. I have a magnetic loop antenna standing behind me, on loan from a friend and I use it to scan the bands. It's compact, easy to tune and one day I'll make more than a single contact on it.
<p>
All this to say that I've been investigating coax stub filters.
<p>
If you're not familiar with the notion, you can cut a piece of coax cable to a specific length and connect it with a t-piece to your antenna feed line. If you do that, depending on the length of the coax you cut, you get interesting effects. These effects include filtering, or notching out frequencies, passing other frequencies and all in all affecting what your radio is able to receive and transmit.
<p>
If you've never set up your radio with some friends nearby for a field day, a contest or a camp-out, you might be surprised to learn that even across the space of a field or a caravan park you'll be able to hear the other station, even if they're not on the same band. You might hear their actual voice, or more likely, you'll hear all manner of overload sounds that essentially show up as noise blocking out the station you're really trying to hear and work.
<p>
Of course, the reverse is also true. When you're transmitting, your friend is hearing the same horrible gunk coming out of your radio.
<p>
One of the ways that you can manage this is to set up filters, either notch filters which reduce the strength of undesired transmissions or pass filters which only allow certain frequencies to get to your radio. Combining these will make your life much easier.
<p>
Coax stub filters are a tried and true method to achieve this and the Internet is full of expert opinion on how to exactly do this. With infinite budget and time, you can try them all out and with your trusty network analyser you can find the combination that works just for you, but in the real world you have a limited amount of coax, money and your lottery winning didn't cover that network analyser.
<p>
I started this process in earnest two or so weeks ago and frankly I'm no closer now than I was then. I'm still in the reading articles stages. I think I'd like to create two sets of band pass filters and connect each set to a radio. If I'm on 10m, I set my radio to use a 10m band pass and set the other radio to use a pass filter for their band. I figure between the two of them I have something that resembles what I'm looking for.
<p>
If wishing made it so.
<p>
To make matters more interesting, I have two rolls of Quad Shield RG6 coax left over from my days climbing roofs and installing satellite dishes for broadband Internet in the bush. If you're familiar with that you already know that this is 75 Ohm coax. Of course none of the documentation I've been reading even talks about using 75 Ohm coax. I like it because it's strong, low loss and I have loads of it.
<p>
I've been reading everything I can get my hands on. Friends have been sending me emails with copies of copies of copies of a hand-scribbled notes written by a guy 30 years ago with the magic combination. I have several of these, all different. This morning I came across some electrical circuits that purport to do the same thing with a handful of components.
<p>
One thing I do know, if the Internet has a thousand answers on how to do something, no-one really knows, or one of them does and is buried among the not-yet completed copies of the works of Shakespeare written by monkeys.
<p>
I'm Onno VK6FLAB
Listen:
Experience comes from doing ...
Foundations of Amateur Radio
<p>
During the week a friend reminded me that the process of determining what's happening within a shack comes with experience. In my day job my whole skill-set can be summed up with one word: "debugging", in all its many and varied guises, fixing code, hardware, business processes, skill-sets, what ever it may be.
<p>
The process is pretty much, figure out what's going wrong, find out what shouldn't be happening and attempt to join the mismatch together with anything from gaffer-tape to good old fashioned hard yakka.
<p>
Back on topic, the question my friend asked was about their WSPR receiver which had stopped making spots. If you're not familiar, WSPR, Weak Signal Propagation Reporter is a way of listening at specific times on specific frequencies for a signal and when received and decoded, publishing the spotted signal on a website.
<p>
Their first thought was the antenna, that's where the signal comes from, so if that's not working, the rest fails. Pretty good first guess at figuring out what might be wrong.
<p>
There is an adage somewhere, not sure of the exact wording, but it goes a little like this: if you don't know where to start, start somewhere, anywhere, and go on from there.
<p>
Based on that the question became: How can I simply test my antenna and should I buy an SWR meter?
<p>
If you're not familiar with how WSPR actually works, it's a radio receiver connected to a computer running software that decodes the signal and reports it across the Internet to a website that logs reports from around the globe.
<p>
That sentence hides a level of complexity that boggles the mind if you start digging, but I'll give you a hint, it's not needed in this case.
<p>
In my own experience with WSPR, my computer would crash regularly and get slower and slower. It turns out that I'd configured it to store a copy of each signal, as an audio file, so the computer drive was chock-a-block full of audio files. End result was crashing.
<p>
I've also had issues with the WSPR site being unavailable and in Australia we're currently in the middle of rolling out our brand new not so shiny National Broadband Network which in turn causes Internet outages all over the place.
<p>
While the antenna was a great place to start eliminating issues, there were several other candidates that could also cause issues, none of which required much in the way of effort to eliminate. As a bonus the antenna was also used for a weekly net and a quick scan with a spectrum analyser revealed that it was working just fine.
<p>
A day later I got a follow-up email, turns out that the station they were listening for, an automatic WSPR beacon nearby had changed frequencies and that meant that it wasn't being received. One plus One equals Three.
<p>
So, the lesson in all this is that two minds are better than one and that you can both be wrong at the same time.
<p>
One thing I really love about amateur radio is that the problem domain is huge. You can think of amateur radio as two stations talking to each other, or you can imagine a place where there is so much variability that exploration in and of itself is the activity.
<p>
Now that I've moved, I should fire up my WSPR receiver and see what gives. Which reminds me, what WSPR spots have you seen and if you're allowed to transmit WSPR with your license, how far have you been heard?
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 6 - short
Foundations of Amateur Radio is now available as an eBook.
<p>
In Volume 6 - Joy of discovery - read about microphone technique, the dead band, propagation maps, melting coax, amateur radio satellites, strange antennas, self-training, SOTA adventures and more.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
I'm Onno VK6FLAB
Listen:
You and the IARU
Foundations of Amateur Radio
<p>
Have you ever considered the infrastructure that exists to make it possible to tune to 7.090 MHz, call CQ and make contact with anyone on the planet?
<p>
In a world where we as radio amateurs share spectrum with radio and television broadcasters, mobile phones, wireless networks, satellites, GPS, drones, wireless headphones, radar, boating, aviation, citizen band, garage door openers, fitness trackers and any other wireless gadget imaginable, not to mention radio astronomy, microwave ovens, meteorological aids, inter and intra car communication, autonomous cars, trains and more.
<p>
The world clamours for spectrum and in among those allocations we find the amateur bands.
<p>
There are 24 million odd people in Australia, a few normal people, but mostly odd and about 14000 radio amateur license holders, that's about 0.06% of the population.
<p>
It's extraordinary that in the last 100 years of radio spectrum allocation we have access to the bands we have. It's easy to forget that in the rarefied air of amateur radio where we have access to an astonishing amount of spectrum how unique we really are.
<p>
Not only do we have a situation where we have access to bands, this is mostly global access. There are exceptions and while bands don't exactly line up, for example 7.090 MHz in Australia and the UK is an SSB calling frequency, but in the United States this is a CW, RTTY and data frequency, still amateur radio, but not the same mode.
<p>
How this allocation exists is a combination of being the first mover, that is, radio amateurs came along and used it before anyone else had any use for the spectrum and the existence of the International Amateur Radio Union, the IARU.
<p>
The IARU is a topic in and of itself, but in essence it's an organisation that exists and has done since 1925 due to radio amateurs combining their efforts. The IARU consists of over 160 member countries which are represented by their peak body, in Australia the WIA, the UK has the RSGB and the US has the ARRL. So, if you're a member of one of those organisations, you in turn are represented at the IARU where volunteers represent you and me on the world stage.
<p>
The IARU has organised the world into three regions that correspond with the International Telecommunications Union, Region 1 is Europe, Africa, the Middle East and Russia, Region 2 is the Americas, Region 3 is the rest, Asia and the Pacific, that includes India and China.
<p>
At some level discussion about the IARU, the role it plays and the processes it has and services it offers is a dry and boring administrative slog. It's not sexy, it's not thrilling, but every once in a while I think it would be a great idea to consider what the world might look like without the IARU and what our hobby might look like had this organisation not existed.
<p>
There are some public activities that the IARU engages in, the Beacon Project, the HF World Championships and the Worked All Continents award. There's the Monitoring System and other activities such as the Amateur Radio Direction Finding or ARDF championships.
<p>
The public relations face aside, much of the activity of the IARU is invisible, going to meetings, making proposals, keeping abreast of new technology and threats to radio spectrum, participating in working and study groups and the administration of all this volunteer effort.
<p>
Next time you call CQ and a station on the other side of the planet answers, consider some of the invisible forces at work that make it possible.
<p>
I'm Onno VK6FLAB
Listen:
Coax Loss vs Connector Loss - now with more coax
Foundations of Amateur Radio
<p>
Recently I spent some time discussing the losses associated with connectors between your radio and your antenna. The traditional wisdom, and I use the word "wisdom" ironically, says that each connector introduces loss into the feed line. There is an understanding that the more connectors you have the worse it is and the more loss you have.
<p>
Jim W6LG did the test, connected up 30 odd connectors and measured. His measurements were done on 14 MHz and on 50 MHz, using 50 microvolts and 1 kilowatt. No discernible difference.
<p>
Of course after I mentioned this out loud the questions started. Why didn't he test this at a usable frequency, something like 145 MHz, or in the GHz band? Then there were those who said that this wasn't a real test and that it should be tested with coax in between the connectors.
<p>
I discussed this all at some length and one idea we had was that perhaps the intersection between the coax and the connector was the problem, that each transition between coax and connector and back was introducing the loss.
<p>
I wondered if there was a way to test this.
<p>
Turns out that somebody already did. Back in July 2015 Jim K9YC decided that this needed to be tested. That's right, another Jim.
<p>
He set up a test with a dozen 100 foot lengths of low loss coax, that's just over 365m of coax. This included two dozen PL259 connectors and 11 barrel connectors. He tested using a calibrated HP generator/voltmeter rig. The total loss was and I quote: "one dB or so less than the loss specified for the cable by the manufacturer". So, the run with connectors was actually better than a single run of coax.
<p>
In case you're wondering, he tested this up to 500 MHz.
<p>
Jim K9YC points out that there is a grain of truth in the loss when using junk connectors which can introduce excessive loss and can overheat because the centre conductor is too small.
<p>
I should mention that this might now debunk the connectors and loss issue, at least up to 500 MHz, but there is something to be said about reducing the number of failure points along the way. Having 35 connections instead of two is an added risk of water ingress, loose connections, short circuits in the connector and potential for other unexpected things like an intermittent connection.
<p>
In the broader scheme of things, on a field day, or a temporary antenna set up, there's clearly nothing wrong with using some connectors to join together some coax. It also means that my investment into coax terminated SO239 connectors was based on poor information, though it does mean that I don't need to carry nearly as many barrel connectors around.
<p>
Perhaps it's time to, as Jim puts it, put this "old wives' tale" to bed.
<p>
In the same document Jim discusses many other questions in relation to coax and stub filters in your HF station. I came across the document while I was looking for information about coax stub filters, since I just participated in another contest where two stations in the same location were interfering with each other and I want to be prepared for next time.
<p>
There's a lot to discuss in relation to coax stub filters, but in essence you create a quarter wave and half wave lengths of coax that are resonant at a range of different frequencies and the combination of these will either pass or block the band you care about. Given that I have a roll of Quad Shield RG6 lying around, I thought I'd try my hand at making a set of these for my next outing. No doubt I'll share my adventures with you as I explore and dig through the pile of information.
<p>
Coax and connectors, stubs and filters, it's all in a days experimentation in this amazing hobby we call amateur radio.
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 5 - short
Foundations of Amateur Radio is now available as an eBook.
<p>
In Volume 5 - Getting on air - read about the perfect SWR, how to become a better operator, what batteries to use, the difference between a propagation forecast and reality, the phonetic alphabet, antenna compromises, Q-codes and more.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
I'm Onno VK6FLAB
Listen:
Coax Loss vs Connector Loss
Foundations of Amateur Radio
<p>
A question that comes up regularly is one about loss, specifically loss in the coax and connectors between your radio and your antenna. The general wisdom is that better coax gives you better results and more connectors is bad.
<p>
Anything with double joiners, or such like is really bad.
<p>
So, essentially we've been taught that we should have the shortest coax possible with as few connectors as possible.
<p>
Pretty fair and reasonable, right?
<p>
During the week I was introduced to a video made by Jim W6LG. Jim has a YouTube channel going back a couple of years with about a 100 videos.
<p>
One video is loosely called Jim measures the loss in coax connectors and 100 foot of RG8X. In case you're wondering, 100 foot is 30m and 48cm of coax. I know this because the United States of America despite appearances to the contrary is actually metric, they defined the inch as being 2.54cm back in February of 1964. Other than driving on the wrong side of the road, they're not too strange and they talk on the air, a lot, so there's that.
<p>
Back to Jim.
<p>
He rummaged through his bits box, the one you have, the one that every amateur has, and if you don't then you clearly need to spend some time being with an Elmer and learning the ropes. Jim pulled out 30 odd connectors, SO239 and PL259 by the looks of things and daisy chained them all together. Jim has been around the block a few times and he has connectors going back to World War 2, so he really did find the bottom of his box to make his video.
<p>
Anyway, he rigged up a testing tool to compare a single connector to 30 connectors. Measuring the difference, showing pretty graphs, lines and scales, the whole bit.
<p>
He even compared 20m to 6m and tested both extensively and even re-did the tests with a kilowatt.
<p>
Then as icing on the cake, you know the one, with a cherry on top, whipped cream on the side, he did the same test with the 30 odd meters of RG8X coax.
<p>
I could leave you hanging here and let you go and find Jim's video, but that wouldn't be fair if you're currently in the middle of your commute to work like several people I know, so I'll share the outcome, but if you get the chance, the 5 minutes of your life that you'll spend with Jim are worth every second.
<p>
So, what was the outcome of Jim's test you ask?
<p>
Surprisingly, there was no discernible difference between one connector and 30 connectors in-line, not at 14 MHz, not at 50 MHz, not at 50 microvolts and not at 1 kilowatt, about 223 and a half million microvolts.
<p>
Using RG8X coax, which sits about halfway between RG58 and RG213 in terms off loss, there was however 22% loss at 14 MHz and 40% at 50 MHz.
<p>
Does make me wonder if it's the coax manufacturers who have been telling us to buy more coax rather than join two bits of coax together with a connector.
<p>
Might have to do that test myself. Better go and start digging through my bits box.
<p>
I'm Onno VK6FLAB
Listen:
Amateur Radio Minimalism
Foundations of Amateur Radio
<p>
The ultimate radio shack is a nirvana that most amateurs I've met strive for all their life. One of the many views I've heard on the topic keeps speaking to me, one of minimalism, less is more, what is the absolute minimum that you can use and still call yourself an amateur?
<p>
As you know, I've recently moved and my shack was packed up into some boxes and is now slowly being unearthed. At the moment there are two antennas, a radio and a power supply. Keen observers will note that this is the same as it was last week.
<p>
I've left well enough alone because of two reasons, one being that I'm trying to catch up on lost work during the move and the time where my internet connection was less than optimal, the other reason being that I've been attempting to work out what I actually want from my shack.
<p>
Unlike my previous QTH, my current location affords me more flexibility, much more, as in four to six times more space to call my own. That's not to say that I was previously living in a shoebox and now I'm in a mansion, just that the distribution of space this time around is working out very well.
<p>
So, I could go crazy, install computers, screens, multiple radios, a work bench, a soldering station, a weather monitoring station, a contest computer and the likes, or I could spend some time enjoying the breathing space around me and contemplate what I should do with this new found freedom.
<p>
Initially I pictured setting up a dedicated DX cluster screen, a propagation screen, write some scripts to show the current maps using something like a raspberry pi, set up a dedicated space for doing contests and figure out how to mount several HF antennas, but the more I think about this, the more I wonder if this is what I really want.
<p>
I've said many times that I adore contesting, it's a pull, a challenge, a bridge I have to cross, a mountain to climb, whatever the metaphor you see, but is that all there is about amateur radio that I enjoy? I know that I'm working on several bits of software, another DX project, some research and other activities, all related to amateur radio, but not specifically contesting.
<p>
The thing I'd like to attempt to avoid, perhaps foolishly, given my less than latent hoarding tendencies, is the clutter that I see in other shacks. They're perfectly homely places, comfortable, full of interesting things, but I'm wondering what a minimalist shack might be instead, think of it as a "tiny houses" equivalent of getting rid of clutter in my life.
<p>
What minimalist successes and failures can you share that helped you along the way?
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 4 - short
Foundations of Amateur Radio is now available as an eBook.
<p>
In Volume 4 - Just get started - follow my journey through the amateur radio community, how to use QSL cards, mobile antennas on HF, licensing requirements, policing the airwaves, the super check partial list, packing up coax, lightning protection and more.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
I'm Onno VK6FLAB
Listen:
What improbable antenna solution works?
Foundations of Amateur Radio
<p>
There is some truth in simplicity. I've mentioned in the past that "suck it and see" is a perfectly valid solution to figuring out if something is going to work or not.
<p>
I've moved into my new home, my new QTH. The roof is colour bond, that's basically a corrugated iron roof, painted in some random colour. I think it's grey, but don't quote me on that, could be green.
<p>
Inside is a mezzanine floor, essentially carving out a space within the roof area. It's going to be my office and radio shack, so after setting up technology, I had a spare 15 minutes and came across a box that had my radio bits inside it. After setting up power I went and combed through some more crates to locate a magnetic mount and the vertical I use on 2m and 70cm in my car.
<p>
The roof beam is held up by a steel post which forms part of the railing that surrounds the mezzanine floor.
<p>
All conventional wisdom tells me that this is a poor place for an antenna.
<p>
So, undeterred with little else in the way of simple options, I stuck my magnetic mount to the steel post with my vertical attached. Of course this doesn't mean that I have my vertical actually mounted vertically, in fact it's not, it's horizontal.
<p>
So, there's one of two steel posts that holds up the steel roof, a magnetic mount stuck to the side of the post with a vertical, running horizontally.
<p>
It keyed up the local repeater the first time. Made some contacts, spoke to three local amateurs to confirm that they could in fact hear me, swapped sides on the post, from parallel to the roof line to 90 degrees off the side with some improvement.
<p>
Now as I said, on paper this shouldn't work. The roof beam runs north-south, the repeater is off to the east of the pitched roof, so the signal isn't making its way off the ends, it's going through the roof, or I've managed to use the roof post as an antenna, or the roof, or both, or the signal is bouncing down, over a metal fence, who knows.
<p>
The point is, it works when anyone you'd have asked about this would have rightly told you that it won't.
<p>
When I asked recently what the ideal shack should look like, one person who travelled a lot pointed out that just enough shack is a good place to start. Right now, I'm a power supply, radio and a horizontally mounted vertical into the minimal shack.
<p>
I was asked if I'd tested HF yet. Seriously, the radio is 15 minutes out of the box. But in a word, yes. I put on a 10m vertical, also mounted horizontally, same magnetic mount and I can hear the local beacon on 10m, 12m and 15m, a vast improvement on my previous HF experiences at home. Overall the noise on the bands seems less than it was in my old house - this could be because of shielding of the roof, or it could just be less actual noise, or because my antenna is mounted horizontally. Previously I had S9 noise, now it peaks at S5, but on average it's around S2-3. This is not a proper test by any stretch of my imagination and while initial indicators are better, this is by no means a definitive test of the HF band.
<p>
For my next trick I'll be taking a closer look at the railing that surrounds my office, It's made from stainless steel stranded wire, the stuff you find on a boat, with seven strands to choose from, in three separate orientations, so plenty of room for experimentation and more if I dare to use the strands on the staircase, seriously, I won't be.
<p>
One thing I will do before I start keying up for the next HF contact is do some electro magnetic radiation research to learn if I'm in the danger zone, or if my family might be exposed to unsafe levels of RF radiation. Normally this isn't an issue with 5 watts when the antenna is on a roof, but now I have it indoors I'll spend some time making sure.
<p>
I still have a magnetic loop on loan from a friend, packed away in a box that I'll unearth in the next couple of days to see what it has to say about the new RF environment.
<p>
As I said this is just the beginning and I've not yet been calling CQ or checking out the local HF nets.
<p>
What crazy set-ups do you admit to, that actually worked, even though they shouldn't have?
<p>
I'm Onno VK6FLAB
Listen:
What criteria do you have for your ideal shack?
Foundations of Amateur Radio
<p>
From time-to-time people move and their shack tends to move with them. For me that move is happening right now, I'm moving all of 900m up the road, a long story in itself, but perhaps best told over a camp fire far from civilisation.
<p>
As I started the process of working out what needed to be done I realised that I made a few rookie errors. The first one, one that I've made before, but at the time my excuse was that I knew nothing about amateur radio - some say I still don't - this time I was busy focussing on above ground power, pole-top transformers and high-speed internet. I forgot to check mobile phone coverage, forgot to bring a radio and forgot to listen on HF.
<p>
I will no doubt find out what the state of these things is when I actually move, in a few days from now, but my rationalisation was essentially, "I'm not able to operate from home as it is, so it won't get any worse and if I'm lucky, it might get better."
<p>
Frankly I didn't have the heart to tell my long-suffering partner that there was yet another condition, you know among the "must have actual proper internet, not the promise of one next year", "must have space for my office" and "a place that can be locked up in the garage". I skipped the "must be amateur radio friendly" tick box for familial peace, and as I said, it cannot get worse and it might get better.
<p>
Looking around my office now, it occurs to me that I'm going to have to remove the coax that runs through the window, which involves either cutting the coax, or de-soldering the connector. I suspect that it will become the most expedient of the two, given that de-soldering involves having to find my soldering iron among the half-packed-up house, cutting looks like it. I'll tell myself that it's good because I'll find out if my coax is waterlogged, but between you and me, it's because I'm impatient to get moving.
<p>
The remaining part of this is the thing that's on the other end of the coax, the metal shiny thing on the roof, known to most of the amateur community as a 10m vertical, a metal rod, resonant on the 10m band, about 2m long, clamped to the gable of my pergola, will have to come down. Of course at that point I'll be off the air.
<p>
No counting how long that will last, but I'm hopeful that a quick-and-dirty magnetic mount will get me up and running shortly after the move.
<p>
Of course in an ideal world I'd already have measured out the future radio-shack, have a room away from the house, insulated, away from the fence-line, lots of backyard with a choice selection of high trees, no noisy neighbours, council regulations that encourage radio amateurs and a coffee machine, a bed and while I'm at it, air conditioning.
<p>
Who am I kidding?
<p>
I'll likely be able to put my radio somewhere in a corner on my desk, much like it is right now and if I'm lucky, I'll be able to be on-air without disturbing the family.
<p>
This all in stark contrast with a friend of mine who asked the community a simple question. Where would you put your radio shack if you needed fast internet and nearby medical services, anywhere in the state.
<p>
The answers were many and varied, from ludicrous to amazing, from off the cuff to well researched, just waiting for the win on the weekend lottery to be able to pay for it.
<p>
Our shack is an integral part of our hobby and while I see some amateurs go out of their way to find and position their ideal shack, I see many more just making do with what they have. No doubt there is a balance to be found.
<p>
I'm curious to hear what criteria do you have for your shack? What things are essential and what would be nice to have. If money wasn't a problem, what would your ideal shack look like and where would it be?
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 3 - short
Foundations of Amateur Radio is now available as an eBook.
<p>
In Volume 3 - Share the fun - follow the third year of my journey, how to make contacts on HF, how to go on-air QRP, propagation planning, how to deal with trolls, online resources and more.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
I'm Onno VK6FLAB
Listen:
What do you know now that you would have liked to have known when you started in amateur radio?
Foundations of Amateur Radio
<p>
Recently I was asked: "What do you know now that you would have liked to have known when you started in amateur radio?"
<p>
The hobby of amateur radio is one filled with generosity. Extreme forms of it. People go out of their way to help, to explain, to loan equipment, to help out, to repair stuff and to participate. In the past I've spoken about the negative aspects of this hobby as well. Belligerence, the warlike aggressively hostile nature of individuals and groups in amateur radio is like nothing I've ever encountered elsewhere, and it needs to be acknowledged.
<p>
In many ways amateur radio is about extremes, generosity against belligerence, very polarising, confusing and challenging.
<p>
That said, amateur radio is a hobby like no other.
<p>
It sits in a field of exploration, of discovery, of invention, challenge and experimentation. Amateur radio navigates between scientific and empirical learning. It's regulated to encourage research and at the same time encourages new entrants into the field with a weekend course. The range between learner and professional embodies the amateur radio community.
<p>
One of the things that caught me by surprise about amateur radio is that nothing is set in stone. You would think with a field based around physics that would not be the case, but given the vast range of variables at play, often "suck it and see" is a perfectly valid way of finding out if something works. I'd hazard a guess that the most frustrating part of asking a question as a new amateur is the answer: "Try it and find out."
<p>
In 1920 H.L. Mencken said: "there is always a well-known solution to every human problem - neat, plausible, and wrong".
<p>
With that in mind be sceptical if an amateur gives you the definitive answer on how to do something. Often the number of variables is infinite and your situation is subtly different from theirs. In that context, the answer "Try it and find out." is perfectly valid, frustrating as it is.
<p>
I started in this hobby just over seven years ago and since then I've continued to collect what I think of as puzzle pieces, bits of information that I carry around. For example, a dit is the letter e because it's the most common letter in the English language. Voltage equals current times resistance. You need a carrier to measure the standing wave ratio. Remember to bring the head unit connecting cable when you go into the field.
<p>
There are thousands of bits of information like that floating in my head. When two collide, I gain some knowledge. The most recent example of that was my explanation on how you could use the offset within a side-band signal to determine if a radio was on the correct frequency. It took a while for me to understand it enough to explain it and when I could, I did.
<p>
For example, right now I'm working through the various types of decibel. You might have thought of a decibel as a particular unit, but actually there is more than one. The deeper you dig, the more crazy it gets. For example, the definition of a decibel in relation to sound appears to exist within an ISO standard, but you can't get that standard unless you buy it. Seriously, a physical standard that you have to buy in order to know what it is.
<p>
Another example is the definition of the Ampere, which involves infinite length wire and the force between them. The mind goes cross-eyed thinking about how to calibrate an ammeter.
<p>
So, to answer the question: "What do you know now that you would have liked to have known when you started in amateur radio?"
<p>
It's complicated. It's challenging and it's like nothing else. Find your own way, talk to people, ask questions and be prepared to be amazed and annoyed at the same time.
<p>
One final comment, amateur radio has its share of "Mostly Harmless" crocodiles, all mouth and no ears, but the overall apt description that comes to mind to describe this fascinating community is "generous and welcoming".
<p>
I'm Onno VK6FLAB
Listen:
How should I promote my contest?
Foundations of Amateur Radio
<p>
The act of telling someone about something is promoting it, not in a marketing sense, just an awareness sense. The act of not telling someone is keeping a secret.
<p>
Radio amateurs, and I have no doubt, people who are not, like to plan things. They set-up contests, on-air activities, organise swap-meets, build websites, write articles, invent things, build stuff, and all manner of other amazing activities. Some amateurs talk about what they've been up to, but most just sit quietly, hoping that their brilliance will be discovered by someone.
<p>
Of course that rarely happens.
<p>
Let's imagine a contest. It's an activity that you'd ideally want other amateurs to participate in, talking to yourself, on your own is like being a broadcaster and I can tell you, that's a tough gig. A contest is about making contacts between different participating people.
<p>
So, your contest, it's going to have rules, a planned outcome, say more QRP activity on 40m, and it's going to run at a particular time. I've lost count of the times where that's the sum-total of effort put into organising a contest. Of course the contest flops, since no-one knew about it, and often that's the end of it.
<p>
So, what can you do to actually get a head start in making this contest work?
<p>
For starters, you should figure out who the audience for this contest is. If you set it up on 160m and aim for beginners you'll have a problem, since they're not allowed on that band. So, the audience is based on the rules of the contest and of course one influences the other.
<p>
Once you've got a defined audience, and no, all the amateurs on the planet is not a valid audience, since by that metric you could also say all the taxi-drivers in New York city, and while that is a defined group, it's unlikely that you'll find much in the way of participation in your amateur radio contest. That's not to say that there isn't a New York cabbie who isn't also an amateur - hi - but their amateur status is not the same as their taxi-driver status, so pick an actual defined audience. The more defined, the better.
<p>
Let's say for a moment that your audience is amateurs who've been in the hobby less than a year who live within 1000 km of you.
<p>
Now your task is to figure out how you're going to talk to them, what you're going to say and how you're going to encourage them to be part of this wonderful contest.
<p>
You could target the local amateur schools, and ask them to send out an email on your behalf to promote your contest, or you could approach the local radio clubs and ask them to promote your thing to their new members. You could seek out local radio nets that cater for new amateurs, you could write articles for the local radio magazine, or you could post comments on your favourite social media outlet.
<p>
None of these things are particularly difficult, onerous or complex, but not doing them means that your contest is doomed before it starts.
<p>
So, now you have an audience and some outlets for communication. What do you say?
<p>
I've seen contest promotions that list the frequencies and link to the rules. That's it. Not very inspiring. I've seen promotions that state that they're aimed at a particular audience, but the rules indicate that you'll need to have a particular license in order to participate because the bands or modes exclude the audience. All these messages achieve is the opposite of promotion. People know to avoid this contest, rather than feel inspiration to participate.
<p>
So what should your message be?
<p>
First of all, it should be written one-on-one. You're listening to me right now. The fact that there are other people also listening is not relevant to you. Every communication is like this. Everyone experiences communication as a message to themselves, to their needs, emotions, desires, motivation, just me and you, talking. Of course there are messages intended for a stage, but this is not one of them. We're not in Wembley stadium and I'm not on stage encouraging everyone to wave their hands in the air right now.
<p>
So, write your message to a single person. The better you can imagine that person, the better the message works.
<p>
The information in the message needs to be heard, so you need to find a way to relate to the person listening, it needs to resonate in some way. You need to be able to elicit a "Noooo", or a "Yes!" from the person listening.
<p>
There's a contest that encourages you to set up a Jolly Roger and speak like a pirate on air, simply to find something that makes it stand out and be memorable.
<p>
Your message needs to do that, stand-out and be memorable.
<p>
The first place to look is inside yourself. What would make you want to do this contest, what would motivate you, how would you benefit from this contest, what would you gain?
<p>
So, find an audience, figure out how to talk to them, determine what you want to say and then do it. Of course, this doesn't just apply to a contest, it applies to courses, to radio clubs, to swap-meets, to technical talks, anything you want to have people come and play.
<p>
What are you waiting for! Amateur radio promotion isn't hard, but you have to actually do it.
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 2 - short
Foundations of Amateur Radio is now available as an eBook.
<p>
In Volume 2 - Find the spark - follow the second year of my journey through the hobby of amateur radio, what's the point of Morse code, making contacts during lunch, Magnetic Loop Antennas, keeping your shack tidy, the identity of your callsign and more.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
I'm Onno VK6FLAB
Listen:
Antenna gain and polar chart magic
Foundations of Amateur Radio
<p>
If you've ever been on the hunt for an antenna, and let's face it, in amateur radio that's pretty likely, you'll get information about the gain of an antenna. Often someone will tell you that this one has 12 dB gain, versus that one which only has 9 dB.
<p>
As an aside, I've seen a few videos where people are comparing sound levels and mention that without the fan, there is only 3 dB less noise. What they don't realise is that 3 dB means HALF the noise.
<p>
The same is true with an antenna. That 9 dB antenna has half the gain of a 12 dB antenna.
<p>
In the past I've talked about gain. It's always in comparison to something else. If I say "that antenna has 12 dB gain", I'm actually saying: "that antenna has 12 dB gain when compared with an isotropic source". To jog your memory, an isotropic source is a theoretical source of electromagnetic radiation. It cannot actually exist. It radiates uniformly in all directions.
<p>
Now when we talk about gain, we're saying that our new funky antenna radiates better in some or other direction than an isotropic source.
<p>
As a consequence of this, it also means that it radiates worse in other directions.
<p>
So antenna gain is a trade-off between radiating everywhere like an isotropic source, and only radiating in one direction like a laser beam. As an aside, a laser beam could be seen as an antenna for light. It radiates much better in one direction than in any other, and given that light is also an electromagnetic radiation, we're still playing in the same area of physics.
<p>
If you've ever shone a torch light onto a wall, you'll have noticed that the light isn't uniform. There are brighter and darker areas. It's the equivalent of differences in gain. Some bits of the light are amplified more than other bits. If you compare it to something like a candle, not exactly an isotropic source, but remarkably close, you'll notice that the light is uniform.
<p>
A torch doesn't shine from the rear, the energy from the light that's missing from the rear comes out the front and that's gain.
<p>
Radio antennas do the same thing.
<p>
In order to compare antennas with each other we've devised several tools, the most common is a polar plot. It's a circle that is divided into 360 degrees, and inside the circle are concentric circles with gain numbers attached to them. Often, but not always, the outside circle has 0 dB as a value and you'll see -10 dB, -20 dB and so-on as you get closer to the middle.
<p>
Weaker signal is drawn away from the outer edge, stronger towards the edge. No signal in the middle.
<p>
As you walk around your torch, you could record the strength of the light. Where it's strongest you'd make a mark on the edge of the chart. Where it's weakest you'd mark towards the centre of the chart.
<p>
If you were to take your torch and take a slice through the middle of your battery, through the reflector, through the globe, through the lens and out to the wall, you'd end up with what a polar chart is displaying.
<p>
Of course you can slice through your torch in any direction and make a chart, but traditionally, you'd slice it horizontally and vertically, or azimuth and elevation - and if you can't remember which one is which, an elevator goes up.
<p>
A torch is generally symmetric, so both charts should be the same, unless your reflector is a weird shape at which point the two charts will likely be different.
<p>
Antenna charts work the same way. The polar graph is showing the signal strength as you walk around the antenna - twice - once for the horizontal slice and once for the vertical one.
<p>
As I said, the outer edge of the chart is set at 0 dB. This is because you need to compare full signal to less signal. If you are comparing multiple antennas and they all have the same 0 point, you can draw them over the top of each other and see their differences.
<p>
This allows you to compare wildly different antennas with vastly different amounts of gain.
<p>
I must also point out that you can get more signal strength in two ways, more gain from the antenna, but also, more power into the antenna. This means that your choice of antenna is dependent on what gain you want and how much you're prepared to pay for it.
<p>
I could light up an omni-directional antenna with 300 kilowatts, or I could use a very high gain antenna and use 5 Watts. It all depends on your purpose.
<p>
Final comment. Beam-width of an antenna, the main direction of radiation, is often based on where the signal strength is half, so 3 dB less than the maximum gain. That location will determine the angle, remember the chart is expressed in 360 degrees, so you'll be able to see the beam-width on the same chart.
<p>
Polar charts, lots of hidden meaning inside a pretty picture.
<p>
I'm Onno VK6FLAB
Listen:
Just enough radio ...
Foundations of Amateur Radio
<p>
In the past little while you've heard me talk about WSPR, Weak Signal Propagation Reporter and I've told you about signals I've heard across the planet. The longest distance at the time was a HF report, 18656 km from Perth to Pennsylvania, very nice indeed.
<p>
I switched to monitoring 6m, 2m and 70cm about a month or so ago.
<p>
My reports had been pretty minimal, from my QTH to the suburb next-door and then two suburbs away. Proof that a station is working, but hardly anything to celebrate or even mention.
<p>
The other day I came across a report a little further away, Perth to Adelaide, 2142 km away. Not world record beating, or even earth shattering, but proof that 6m propagation does have its moments now and then.
<p>
Then a surprise contact, Perth to The Rock, not the one in the middle, or the one with the wave, the one on the Olympic Highway between Wagga Wagga and Albury, 2899 km away with 20 Watts on 6m.
<p>
My reports aren't particularly far or amazing. You might recall Wally VK6YS who made a contact on 6m between Perth and Israel. He'd been at it for a little while, longer than I've been an amateur, but not quite as long as I've been the apple in the eye of my mother. 38 years it took for Wally to make that contact.
<p>
So why am I making any mention of my little achievement?
<p>
Simple really, my station and Wally's station are nothing alike. He had a large beam on 6m located on a property with few noise sources and his patience paid off.
<p>
My station consists of a 10m antenna, that is, it's not 10m tall, it's resonant on 10m, and happens to also manage 2m. I've not actually checked to see what 6m on this antenna looks like, perhaps a project for another day, but it sits there, clamped to a metal pergola at the peak of a corrugated iron roof and connected via 20m or so of RG58 coax, cheap RG58 coax, connected to my radio that I use to host F-troop most weeks.
<p>
I have to restart my WSPR node monitoring software several times a week since the Windows XP notepad computer it's running on crashes regularly. I have to remember to open the squelch when I finish F-troop and connect the WSPR node back up and I have to make sure that there's enough empty disk-space to make sure that I can actually log stuff.
<p>
This isn't a sob-sob story, woe is me, my station isn't a massive station. It's more about that you can achieve these kinds of things with small and minimal resources.
<p>
One of my friends is doing really well with a USB TV dongle decoding WSPR on a Raspberry Pi, others are using thousands of dollars of gear and everything in between.
<p>
The point is that you too can get started without massive expense. A simple radio, something to run WSPR, which can be a Raspberry Pi, an antenna of sorts and you're on the way to check out what propagation is like around your QTH in your neck of the woods.
<p>
Amateur radio doesn't have to be expensive, it doesn't have to be extensive, it doesn't even have to be elaborate, it can just be enough.
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 1 - short
Foundations of Amateur Radio is now available as an eBook.
<p>
In Volume 1 - Join the hobby - follow my initial journey through the community, what to buy when you start, how to participate in the community, things to practice, what the first steps look like once you have a license, playing in radio contests, encouragement and sharing.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
I'm Onno VK6FLAB
Listen:
Virtual Radio
Foundations of Amateur Radio
<p>
There is a feeling of anticipation in the air, the year has started, there are so many different ideas bubbling through my mind that I feel like an excited puppy dog wagging its tail.
<p>
I've been playing with a wonderful piece of software called GNU Radio, more on that in a moment.
<p>
So, I have for a while been dissatisfied with the offerings of SDR software. There is lots of development going on, lots of new toys being invented and many different hives of activity in this area.
<p>
It's not unlike the progression from reel-to-reel based radio broadcasting via VHS tape, to computers with audio files. There are lots of solutions solving specific problems, but there are also a group of solutions looking for a problem and only time will sift out which one is worth the effort.
<p>
In amateur radio we deal with valves, resistors, capacitors, inductors, transistors, integrated circuits, crystals, connectors, solder and many, many different physical things.
<p>
I'm a computer guy, have been since I was in primary school. I grok computers, more-so than any aspect of anything else. Amateur radio was intended as an escape from this world, but initially to my dismay, but now to my delight, computers are making serious inroads into the hobby. Not just as peripherals that take care of logging, messaging, propagation forecasting and the like, but as integral parts of the radio.
<p>
I looked at GNU Radio several years ago and wasn't able to understand what it did and how it worked. I didn't have enough in the way of radio skills or vocabulary to get started, but in learning about my hobby I now have a much better understanding.
<p>
GNU Radio is a tool, a piece of open source software, that allows you to build circuits inside a computer that process information. Not unlike how filters, amplifiers and oscillators do this inside a physical radio.
<p>
If you want to change the behaviour of a radio, you need to alter a circuit by changing components, or re-design the circuit entirely and re-build it. Hours of planning, soldering, testing and the like, just on a hunch or an idea. It's how we've been doing development for centuries.
<p>
GNU Radio allows you to tweak a radio on the spot, in real-time, and see what it does. The feedback loop is immediate. You build up a sequence of blocks, an oscillator, a filter, a combiner, splitter, decoder, spectrogram, waterfall, whatever and if you need it do do something else, you either swap out one of the blocks, or change one or more parameters, better still, replace a fixed parameter with a slider so you can change it while it's running to see what happens.
<p>
For example, displaying a Lissajous figure in the real world involves two signal generators, cables, an oscilloscope, power, gain settings, timing, several hundred, if not thousand dollars worth of gear. In GNU Radio it involves two signal source blocks and an oscilloscope block, joined together. All there, three blocks, two lines and it's working.
<p>
Making an FM receiver in GNU Radio involves a source of radio frequency information, say a $20 RTL-TV dongle and an FM decoder block. You can display it on a waterfall with a third block, or listen to it with an audio block.
<p>
To make matters even more interesting, you can build your own blocks, transmit if your radio is capable and test all of this without ever needing to go to the local electronics store or heat up a soldering iron.
<p>
I have no doubt that this changes amateur radio for me and I'm fairly sure it will do the same for you.
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 6
Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics.
<p>
In Volume 6 - Joy of discovery - read about microphone technique, the dead band, propagation maps, melting coax, amateur radio satellites, strange antennas, self-training, SOTA adventures and more.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
Amateur radio is a thousand hobbies rolled into one. I hope you find your way.
<p>
I'm Onno VK6FLAB
Listen:
Building a better community?
Foundations of Amateur Radio
<p>
A week or so ago I watched a movie that was simultaneously the funniest and saddest movie I'd seen in a while. "Pecking Order". It follows members of the Christchurch Poultry, Bantam and Pigeon Club in the lead up to the New Zealand National Championships, as they battle history and each other in a quest for glory and for the love of their birds. Think "Best in Show" with Chickens.
<p>
While watching, all I could see was squabbling radio amateurs. We're having a similar situation in the Wireless Institute of Australia. There is evidence of gross financial mismanagement, claims and counter claims, Directors with an axe to grind, lawsuits and feathers in the mail. I understand that the Radio Society of Great Britain went through similar disruption several years ago.
<p>
The ARRL is also going through upheaval right now. Rules, conduct unbecoming, expulsions and gag-orders abound.
<p>
All these experiences deal with how a board conducts itself, how individual members react and how the main membership just wants to get on with things.
<p>
Today I read an article in CQ Magazine, titled "We Have Met the Enemy ... and He Is Us".
<p>
It leads me to wonder, what is it about being on a board that causes you to become entitled? What is it about being a radio amateur that makes you feel entitled to belittle and ignore those around you? What is it about our community that is toxic and detrimental to its survival?
<p>
No doubt as I become older and perhaps wiser I'll get personal insight into these attributes when some young turk comes along and puts me firmly in my place, but for now, I'm the young turk, and you can keep your quinquagenarian jokes to yourself.
<p>
I've heard it said that if an organisation is eating itself, let it die. There is something to be said for that sentiment. It causes new structures to be formed, new processes to be created, new ideas to propagate and new people to participate.
<p>
The thing is, doing this also kills off history, it kills off a knowledge base, it destroys lives, it makes for loss of productivity, loss of investment and it is just plain bad for business.
<p>
When I was growing up I was told of an organisation that would split its territory in half and form two new organisations once it hit 20 or so employees. Each new organisation would carry on, splitting in half as it grew. The idea was that if you had more people than that inside a company it became unwieldy. I don't know what's become of that organisation, what it's called, or even if it even still exists. I'm using it as an example of new thinking, a new way of trying to build an organisation, a new approach.
<p>
What kinds of new approaches could we come up with for our representative bodies in amateur radio? For that matter, what new approaches could we imagine for ourselves and our community?
<p>
There is a very powerful quote by Margaret Mead: "Never doubt that a small group of thoughtful, committed, organised citizens can change the world; indeed, it's the only thing that ever has."
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 5
Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics.
<p>
In Volume 5 - Getting on air - read about the perfect SWR, how to become a better operator, what batteries to use, the difference between a propagation forecast and reality, the phonetic alphabet, antenna compromises, Q-codes and more.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
Amateur radio is a thousand hobbies rolled into one. I hope you find your way.
<p>
I'm Onno VK6FLAB
Listen:
What is amateur radio?
Foundations of Amateur Radio
<p>
What is amateur radio? What's not part of the hobby and what is?
<p>
The more you dig into this, the deeper the rabbit hole goes. I'll start with an analogy to set the scene.
<p>
In aviation, Sir George Cayley was the first person to investigate heavier-than-air flying vehicles. He invented the aeroplane in 1799. The first full-sized glider, built in 1849 carried the first person in history to fly, the ten-year-old son of one of his servants. Since then the Wright brothers made their flight at Kitty Hawk. We saw the invention of commercial aviation, the turbo prop, the jet engine, the space-shuttle, helicopters, drones, rockets, hot-air balloons, the Hindenburg, the Goodyear blimps, hang-gliders, gyro-copters and many, many other contraptions.
<p>
Each of those are considered aviation and the person controlling the device is considered a pilot.
<p>
In amateur radio we talk on the radio.
<p>
We also create repeaters and talk on them. We link them together using what ever technology is available. We make it possible to connect to such networks using software such as Echolink, AllStar Link, IRLP and other internet based systems. We create digital networks with DMR, use WSPR to exchange information, make contacts using CODEC2, have contests using CW and Morse code.
<p>
We build software defined radios where we use computers to decode and encode radio signals, test back scatter using all manner of signal processing, use packet radio, RTTY, Hellschreiber and bounce signals off the moon and nearby meteors or an overflying aircraft.
<p>
We make auto-tuners with a Raspberry-Pi or an SWR meter with an Ardiuno. We build valve based amplifiers and program mp3 voice-keyers, GPS lock radios, map propagation using the internet and have a rag chew on the local 2m repeater.
<p>
We investigate 13cm propagation, do experiments with amateur television and we set up radio stations on top of mountains, in light houses and on remote islands.
<p>
All of this is amateur radio, and frankly I've only just scratched the surface.
<p>
There are heated discussions about if a linked repeater using the internet to create the link is real amateur radio or not, whether using your mobile phone as a node on the Echolink network is real amateur radio or not, if using a computer to create contacts on a digital mode such as JT65 is real radio or not.
<p>
Each of these questions highlights a misconception about our hobby.
<p>
There are no boundaries in amateur radio. We're a bunch of inventors, mavericks, people who attempt the unthinkable, try the impossible and make progress.
<p>
There are people who are passengers on planes, and there are people who fly them. There are people using technology and there are people who invent it. We have a unique perspective as a community. We have the ability to imagine something that doesn't yet exist. Why would you spend any energy on whether that thing is real amateur radio or not?
<p>
Amateur radio is a myriad of things, some of them related to antennas and radio spectrum, some not. This hobby is what you make of it, so go forth and invent something, try something, get on air and make some noise!
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 4
Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics.
<p>
In Volume 4 - Just get started - follow my journey through the amateur radio community, how to use QSL cards, mobile antennas on HF, licensing requirements, policing the airwaves, the super check partial list, packing up coax, lightning protection and more.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
Amateur radio is a thousand hobbies rolled into one. I hope you find your way.
<p>
I'm Onno VK6FLAB
Listen:
No Onno, it's not slippery and other lessons ...
Foundations of Amateur Radio
<p>
There is a saying in my family, which I'll translate into English for you, "No Onno, it's not slippery."
<p>
This came about when I was ten or so and cycling with my grandmother. It was the middle of winter, it was cold, there was the promise of snow in the air, but nothing had actually fallen. On the little plants, twigs is probably a more accurate term, dotted alongside the cycle path you could see little signs of frost. I was cycling on my shiny new bike and my grandmother was following behind. We came up to a corner on the cycle path and from behind my grandmother called out that I should be careful going around the corner because it was slippery.
<p>
Being the indestructible ten year old, I called back: "No grandma, it's not slippery." at which point I fell flat on my face.
<p>
A few years ago I went on a camping trip with my local club to participate in a contest. One member had a tray-top ute and the idea that we could use that as the base of operation. We planned on putting up a 10m Yagi at the top of a pole. Before we started the process I was asked to test the antenna. I plugged it into my radio, keyed up the PTT and noted that the SWR was as expected, good to go. We then set about attaching the antenna to a telescopic mast. The mast is one of those awkward contraptions. Each segment is about 2.5m tall and standing on a ladder on the back of the ute is just enough height to get to the top of the segment, so you can push up the next and clamp it down.
<p>
The segments are made of mild steel, so you need to be careful to keep the whole thing straight, guy-wires everywhere, people scattered all around holding on for dear life and needing a spanner to clamp down on the next segment because the locking pins had long vanished or ceased working.
<p>
About 2 or so hours later we finally had this contraption in the air. Using the Armstrong rotator - a rope that you pull the Yagi around with - we could point the antenna and life was good. We had taped down the coax as we went, put in strain relief, got the whole thing just right.
<p>
Plugged it in and whoa. What happened? The SWR was through the roof. No match on any band, all over the shop. Head scratching and animated discussion followed. After a little while one of my friends asked me if I'd tested the antenna. I confirmed that I had. They'd even seen me do it. More head scratching, more animated discussion.
<p>
I was again asked if I'd really tested the antenna. I confirmed that I had. They asked me how I tested the antenna. I showed them. I plugged in my radio, keyed the mike and showed them the SWR meter. All good. What's the problem?
<p>
At that point I was taught about having to actually put a signal out over SSB to test. If I'd used a mode like FM, or PSK on my radio, all would have been revealed. But no sound, means no power, means no standing wave ratio, since there's nothing to bounce.
<p>
I am reminded regularly of this event whenever I meet my friends, not as snappy as "No Onno, it's not slippery", but memorable none-the-less.
<p>
During the week I went to disconnect my radio. It had been sitting there for a fortnight monitoring WSPR signals on 6m, 2m and 70cm. If you recall, I set it up a couple of months ago to monitor the HF bands. I've not yet done the final analysis on that, but I figured I should see if I could monitor the VHF and UHF bands. I attempted to set my radio up with two antennas, but WSJT-X doesn't seem to like doing both HF and VHF monitoring in the same band plan. It complains with an alert that you have VHF mode turned on when you're monitoring HF and stays quiet when you're monitoring VHF, so in the end I turned off HF monitoring and started listening to 6m, 2m and 70cm.
<p>
After two weeks of nothing, I turned it off, no reports, no point.
<p>
A couple of amateurs contacted me and asked me if I was still monitoring, so I turned it on again. About a week later, I had to turn it all off overnight with a thunderstorm, but the next morning I turned it all on again and left it running. I got a few more emails from amateurs asking if I was hearing their signals. I even set-up a plan to do some testing this weekend, since we confirmed that I was listening to the correct frequency, but still not able to hear local 6m transmissions.
<p>
As I said, during the week I went to disconnect my radio. I turned off the computer, turned off the power supply and went to disconnect the antenna.
<p>
At that point I discovered that I'd been monitoring WSPR for the past fortnight or so without an antenna connected. For icing on the cake, this morning I discovered that the squelch was set for my FM use on the local repeater, so unless the WSPR signal was coming in loud and proud, even with an antenna connected, I would not have managed to hear it.
<p>
All giggling aside, clearly doing something and failing, sometimes spectacularly, sometimes quietly to yourself, is the way to learn. I wonder what little adventures your life shared with you and what lessons you learned along the way. Feel free to share, I promise I won't laugh, much.
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 3
Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics.
<p>
In Volume 3 - Share the fun - follow the third year of my journey, how to make contacts on HF, how to go on-air QRP, propagation planning, how to deal with trolls, online resources and more.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
Amateur radio is a thousand hobbies rolled into one. I hope you find your way.
<p>
I'm Onno VK6FLAB
Listen:
Amateur Motto: Do No Harm
Foundations of Amateur Radio
<p>
The social aspects of our hobby are a never ending feast of variety. Since the requirement for becoming an amateur is that you're interested, the assortment of people who arrive at our doorstep can be described as a motley crew.
<p>
I once stood in a room with radio amateurs and if I recall correctly, between us we had a surgeon, a naval officer, a sailor, a truck driver, a hiking enthusiast, a computer professional, young and old. Some were retired, others hadn't started their careers, there were wealthy people and people on welfare. Some with university degrees, others without.
<p>
I participate in a weekly lunch, called PRAWNHEADS, been going for 25 or so years. The name is an acronym for the Perth Radio And Wireless Noodle House Eating And Discussion Society. We have a lunch with people from all over the place, visitors from overseas, random interstate drop-ins, new and very experienced amateurs, all mixing it together for an hour or so. If you're ever in Perth on a Wednesday for lunch at noon, you should look it up.
<p>
Most of my life I've been a computer geek. Some of the time I was a broadcaster on national radio, an ultra-light pilot and I'm sure there were other phases I've skipped over, being a sea-scout comes to mind for example. In those pursuits I found myself surrounded by different people, but the range of interests and backgrounds was never as wide as those that seem to be attracted to our hobby of amateur radio.
<p>
I'm raising this because it pays to think about this every now and again. People with different backgrounds have different experiences, different expectations, they communicate differently, have different vocabularies, want and expect different things and while the pull of amateur radio brings them into the room, the interaction with other humans is what keeps them there.
<p>
I spend varying amounts of time online in various discussion groups related to amateur radio and a vast range of communication styles is right there in front of you. Some people are brief, to the point of being perceived as abrupt, others never seem to get to the point and in-between them are the peacemakers who attempt to explain what is going on.
<p>
It has been pointed out to me that I have a particular communication style that sometimes causes people to misunderstand my intent. For example, I regularly send single word emails with the word "Done", or "Huh?" From my perspective, this is perfectly clear. You write an email for me to do something and I write back "Done" when I'm finished or "Huh?" when your request makes no sense to me.
<p>
We are a hobby of communication, supposedly. My experience is that we're pretty good with coax, soldering iron, antennas and making a camp site, but our communication skills let us down. We're geared up for talking to people like ourselves, but when we're confronted with people from different backgrounds, often the pitchforks, feathers and tar come out. People take offence, even when none was given, feuds start, people ostracise each other and friendships end.
<p>
I get that not all humans get on with one another, but given the same interests, amateur radio, given that we're about communication, you'd think that we'd spend a little extra effort with this.
<p>
Don't get me wrong, disagreements happen all over the place, amateur radio is no different, but looking at the eclectic bunch that we are, it does appear that we have more than our fair share of bullies, discrimination, acrimony and dissent, not to mention the self-appointed police men, the armchair lawyers and those subject matter "experts".
<p>
I recently pointed out to a new member of our community that amateurs are in the words of Douglas Adams "Mostly Harmless".
<p>
At this time of the year I think it's a good idea to spend a few moments to consider if something you said or did, could be learned from and improved. I'm sure I'll fail spectacularly on regular occasion, but I do know that I'm never intending to do harm and perhaps that might be a good motto for our hobby.
<p>
Do No Harm.
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 2
Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics.
<p>
In Volume 2 - Find the spark - follow the second year of my journey through the hobby of amateur radio, what's the point of Morse code, making contacts during lunch, Magnetic Loop Antennas, keeping your shack tidy, the identity of your callsign and more.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
Amateur radio is a thousand hobbies rolled into one. I hope you find your way.
<p>
I'm Onno VK6FLAB
Listen:
How does Single Side Band work?
Foundations of Amateur Radio
<p>
A little while ago I spent some time discussing how to test if your radio was on frequency. It generated lots of comment and email with various suggestions on other ways to do this test, but it also caused one listener to ask the question, what's this Upper Side Band and Lower Side Band thing you're talking about?
<p>
In the past I've discussed the history of these two, but I've gone back to check and it doesn't appear that I've ever actually explained what exactly Upper Side Band and Lower Side Band might be and how they work and more to the point, why they're important.
<p>
Let's start where you find these modes. In amateur radio, some bands use Upper Side Band and some use Lower. From a usage perspective it's pretty straightforward, but not obvious. Essentially everyone uses Upper Side Band all the time, except radio amateurs below 10 MHz. There is one exception in that, the 60m band - 5 MHz - uses Upper Side Band.
<p>
The mechanics aside, what is the point, how does it work and why does it matter?
<p>
If you've ever seen an AM broadcast via a waterfall display or on a spectrum analyser you'll have seen a symmetrical picture with a big spike in the middle. The spike in the middle is the carrier and the two sides are duplicate copies of each other.
<p>
If you were to do some math, you'd discover that the spike accounts for 50% of the energy that's embedded within the AM signal and you'll realise that doubling the other halves takes care of the other 50% of the energy.
<p>
If you eliminate both the spike and one half, you end up consuming 25% of the original AM signal - in terms of energy. That essentially means that you can now spend all of that available energy in your transmission and in effect get a signal that's four times stronger than the original AM signal. A better way to say that is, Single Side Band is four times as efficient as an AM signal.
<p>
Now if you took the right half of the signal, you'd end up with an Upper Side Band signal, and if you took the left half of the signal, you'd end up with a Lower Side Band signal. The signals are identical, but they're reversed.
<p>
From a technical perspective, the Upper Side Band signal represents your audio from left to right. Low, or base frequencies on the left and high or treble frequencies on the right. A Lower Side Band signal reverses that, which is why a voice sounds unintelligible if you get Upper Side Band and Lower Side Band mixed up.
<p>
The alignment of the radio to a specific frequency works because you can map the audio frequency directly to the tuning frequency. That might not be immediately obvious, but let's imagine an Upper Side Band signal at 10 MHz.
<p>
At exactly 10 MHz, the audio frequency of 0 Hz is represented, at 10.001 MHz the audio of 1 kHz is represented and at 10.002 MHz, the audio of 2 kHz is represented. If your radio is off frequency by say 50 Hz, then the sound you'll hear will be off by 50 Hz across all of those. So 10.001 MHz won't sound like 1 kHz, it will sound like 950 Hz and 2 kHz will sound like 1950 Hz.
<p>
On the other side, if you flip to Lower Side Band, 1 kHz will sound like 1050 Hz and 2 kHz will sound like 2050 Hz.
<p>
Upper and Lower Side Band, nifty solution, better signals, less bandwidth use and all in all a great way to play with radio.
<p>
Remember, everyone uses Upper Side Band all the time, except for radio amateurs below 10 MHz but not on 5 MHz.
<p>
I'm Onno VK6FLAB
Listen:
eBook Volume 1
Foundations of Amateur Radio is now available as an eBook. Six years in the making, after much prodding from fellow amateurs, the edited transcripts of this podcast are now available as a series of eBook volumes. Covering our amazing hobby with short discussions about hundreds of different topics.
<p>
In Volume 1 - Join the hobby - follow my initial journey through the community, what to buy when you start, how to participate in the community, things to practice, what the first steps look like once you have a license, playing in radio contests, encouragement and sharing.
<p>
Search for my callsign - VK6FLAB - on your local Amazon store to have a Look inside.
<p>
Amateur radio is a thousand hobbies rolled into one. I hope you find your way.
<p>
I'm Onno VK6FLAB
Listen:
60 years of amateur radio
Foundations of Amateur Radio
<p>
This morning I spoke with two amateurs on-air. Not that surprising, since I was hosting a weekly net called F-troop for new and returning amateurs. Both amateurs came on-air for the first time in our net, one licensed sixty years ago, the other six days ago.
<p>
It didn't strike me until long after the net had finished that these two amateurs have a completely different experience in this shared community. One started in a world where megacycles were common, the other knows them as megahertz, one purchased their radio in parts, the other purchased it online, one heard Donald Duck sounds and needed to read about a new mode called Single Side Band, the other is going to be reading about digital modes and how they work, one was dealing with analogue television interference, the other is dealing with plasma screens.
<p>
Both these operators share many things. They are both licensed radio amateurs, both have the opportunity to participate in contests, attain their DXCC, pull out a soldering iron, participate in social activities and become members of their local radio club.
<p>
If during their first year as an amateur both of them read Amateur Radio magazine, the members' periodical published by the Wireless Institute of Australia, they'd both find the rules and the results of the Rememberence Day contest, field days, letters to the editor, instructions on how to build antennas, including detailed instructions on building a 2m Yagi, information from the QSL manager, DX activity reports, the new Australian call book and information about the local news broadcast which continues to go to air on Sunday morning at 9:30am local time.
<p>
In the intervening sixty years amateur radio has changed a lot, but it's also stayed the same. A radio from 1957 will still be able to communicate with a radio from 2017. Imagine that for a moment. Electronics during those sixty years saw countless dramatic changes. For example, Fairchild Semiconducter one of the pioneers in the manufacturing of transistors and integrated circuits was founded in 1957.
<p>
Imagine that, the introduction and obsolesence of transistors within those sixty years. The first integrated circuit build by Jack Kilby in 1958 was a phase shift oscillator, consisting of one transistor and a handfull of capacitors and resistors. Today an integrated circuit contains 25 million transistors per square millimeter with some chips being up to 600 square millimeter in size, that's 15 billion transistors.
<p>
The mind boggles what has happened in those sixty years, but the most satisfying part of all this is that both these amateurs can come on-air, join a net and participate in the hobby today.
<p>
If that's not the representation of an amazing hobby, then I don't know what is. Thank you to Sandy VK6FBHW and Brian VK6DAD.
<p>
I'm Onno VK6FLAB.
Listen:
Leave judgement outside the shack ...
Foundations of Amateur Radio
<p>
Today I'm here to tell you that I'm in the process of writing a book, actually seven of them, and to be precise, there's more of editing than writing, since I'm putting together all of my podcast efforts over the past seven years. Nice how that works out, seven years, seven books.
<p>
Most of the effort is in proof-reading my work. Do I spell radio amateur with capital letters, or not, do I use my word-processor to replace all occurrences of radio amateur without capital letters and what happens when I refer to them as radio amateurs instead? You get the drift, lots of minutia, consistency and every now and then a little edit to make a sentence make sense to a reader. As an aside, if I don't get distracted by life I'm planning to publish in the next week.
<p>
The unexpected joy I'm getting from this experience is to read about my adventures and to remember some of the adventures that you have told me about, things I've been working on, events that you and I attended, contests, victories and frustration.
<p>
One thing I've noticed, something that you're likely to observe once in a while by accident, is the immense variety of activities that encompass this wonderful hobby.
<p>
There are build projects, activations, social outings, research activities, laughter, joy, disgruntlement, dissatisfaction and triumphs. I've said many times that this hobby of ours is 1000 hobbies in one and reading back, I suspect that 1000 is underselling the experience.
<p>
Going back also shows that learning Morse code has been on the books for a long time and clearly I'm stumbling on some roadblocks there. My DXCC adventures continue to grow one contact at a time, my mobile setup is working well compared to other methods of activating my station and new adventures appear just around the corner waiting to be discovered.
<p>
I'm in the middle of my next adventure. Adding crystal filters to my radio, installing a temperature compensated crystal oscillator, finding out about the drift and frequency accuracy, all these are part of a much larger project. The next step is finding a suitable antenna. I'm still on the fence between building and buying. It's a joint decision with a fellow F-call, and we're working through this adventure together to see where it might lead.
<p>
Our skill-set is completely different, with different perspectives on the same thing, different tools we bring to bear on the challenge we've set ourselves and that in and of itself is a fun experience to have. We've spent some time together talking about the landscape we're stepping into and I think it's safe to say that we can both learn a lifetime of knowledge from the other person, if our life outside amateur radio doesn't intrude - hi hi.
<p>
The point of this observation is that I've noticed over the years that there are amateurs who leave the hobby, never to return. Some would say: "Good riddance!", but I think that given the infinite breadth of this hobby and community, each of those people leaving makes for a poorer experience for them, and also for us.
<p>
I'll be the first to admit that I have disagreements with fellow amateurs, sometimes very strong disagreements. I know that this is true among other amateurs as well. This is not particularly unusual in a technical pursuit like our hobby, I see it in my professional life in computing as well.
<p>
The thing that should set us up for a better experience is that we're all about communication in this hobby, but there are times when I wonder if we just pay lip-service to that notion, rather than attempt to be tolerant, inclusive and welcoming. Perhaps it would be wise to add another thing that should be left out of the ham shack, together with talk about religion and politics, perhaps we should leave judgement at the door as well.
<p>
I think it would be a good idea to learn how to do that, perhaps bite our tongues a little more, take a breath, ask the other what they're thinking, rather than rant back and forth between two individuals who can't stand the sound of the other person's voice.
<p>
I note that I took a little detour there, but I think it's important to note that this hobby isn't all cookies and cream, that there is discussion, argument and dissent. I think that we are in a unique position to do something about it.
<p>
As for my adventures, they always seem to just be beginning. There's always something new to discover, something new to build, to do, to experience. I've said it before and I'll say it again: "Amateur radio, what a hobby. Tell your friends."
<p>
I'm Onno VK6FLAB
Listen:
How can you measure what frequency your radio is on?
Foundations of Amateur Radio
<p>
The frequency you listen and transmit on in a modern radio is derived from a crystal master oscillator, in my case 22.625 MHz. That master frequency is multiplied and divided to determine the final frequency. To get to 2m you need to multiply by 6. To get to 70cm, multiply by 20. Similarly, to get to 40m, divide by 3.
<p>
Any slight variation of crystal frequency has an impact. 100 Hz variation in the master oscillator causes the radio to be off by 600 Hz in 2m, or 2000 Hz in 70cm. The higher you go the bigger the error.
<p>
This leaves us with two problems. If the crystal changes frequency over time, your radio wanders with that change which is especially noticeable on the higher frequencies. I've previously discussed how you can deal with the variation by correcting for temperature.
<p>
The other problem is the actual absolute frequency. If the radio is set-up for a crystal with one frequency and you replace the crystal with a different one, how do you know what frequency you're actually on? Your dial says one thing, but is that the actual frequency? How do you measure any difference?
<p>
Is a new radio the same as an old radio, does the frequency change over time?
<p>
Measurement is the act of comparing two things. Think of a ruler, wooden stick with markings on it. If the lines on the stick are not drawn in the right place, anything you measure with that stick will not match other sticks. That won't matter if you only ever use your stick to build everything, but typically you use parts supplied by someone else with their own measuring stick.
<p>
In your radio the same is true. What the actual frequency is doesn't matter until you need to compare it to the frequency of someone else. Like say, another radio station.
<p>
The first thing we need is something to compare with, a reference frequency. As it happens there are several of those around. As an example, you'll find reference broadcasts on 5 MHz, on 10 MHz, 15 MHz and 20 MHz. There are countless other frequencies where you'll find radio time signal stations. These stations broadcast on a steady frequency with a defined signal that you can use to do measurements against, even your local broadcast stations have a carrier that you can get started with.
<p>
A typical radio time signal will be an AM station with all manner of information encoded on the transmission. You can tune your radio to the station and hear a talking clock, second marks etc. Unless your radio is seriously out of whack you're unlikely to be able to notice any frequency errors.
<p>
If you tune to the same station with side-band you'll hear some artefacts, but essentially you'll hear nothing. However, if you tune slightly off frequency, you'll hear a tone. This tone is the central carrier frequency and it's very accurate.
<p>
At this point you can do many things. I'll cover one of them.
<p>
I'll explain this with 10 MHz.
<p>
If you set your radio to Upper Side Band and tune to 9.999 MHz on your radio, you should hear a 1 kHz tone. Similarly if you set your radio to Lower Side Band and tune to 10.001 MHz you'll also hear a 1 kHz tone.
<p>
In essence you're listening to the carrier as a 1 kHz audio tone.
<p>
You can swap between the two frequencies, by setting one on VFO-A and the other on VFO-B and switching between them with the A/B switch on your radio. If the tone changes, your radio is off frequency. How much off frequency is determined by the difference between the two tones. By lowering both frequencies by the same amount, or raising both by the same amount, one of the tones will go up while the other one goes down and vice versa. Once you've got both the tones the same, write down both frequencies. Split the difference and you'll know what frequency your radio thinks 10 MHz is on.
<p>
You'll need a radio with both Upper and Lower Side-Band and the ability to switch between two frequencies and before you get started, you need to make sure that your radio doesn't have any frequency changing stuff turned on, RIT, Clarifier, Offset, whatever it's called on your radio. All of them need to be off.
<p>
There are countless other ways of doing this, a procedure called zero-beating with a signal strength meter, using a tone and listening for a wobble in the sound, using an external second receiver and zero beating against that, using a computer to generate tones, using the FMT software included with the WSPR software and likely many more.
<p>
The point of all of these processes is to detect a difference where there shouldn't be one.
<p>
One final comment.
<p>
The most accurate process at this time without specialist measuring equipment is by using your WSPR enabled computer and the FMT software that's included. I'll look at that next time if I can understand what Joe K1JT wrote on the subject.
<p>
Happy measuring!
<p>
I'm Onno VK6FLAB
Listen:
How does a Temperature Compensated Crystal Oscillator work?
Foundations of Amateur Radio
<p>
You know when you walk down the street and you lift your foot and all of a sudden you realise that you stepped in something and now it's stuck to your shoe?
<p>
I had that feeling during the week.
<p>
Last week I mentioned that I had purchased a TCXO, a Temperature Controlled External Oscillator. Lowell NE4EB set me straight by pointing out that XO stood for crystal and that TCXO stood for Temperature Compensated Crystal Oscillator, which then lead me on a merry goose-chase trying to learn about all that.
<p>
I mention this because while the stickiness on my shoe kept me busy, it also highlighted that I'm still a babe in the woods on a steep learning curve to knowledge with some roadblocks, diversions and potholes along the way.
<p>
That reminds me, if you ever feel the urge to pull me up on something I've said, you can email me via my callsign at gmail.com.
<p>
So, how does this Temperature Compensated Crystal Oscillator actually work?
<p>
Without getting into the circuitry behind the scenes, as I mentioned previously, a crystal oscillates and the frequency is dependent on temperature. Turns out this is a predictable curve, which makes it possible to account for changes in temperature.
<p>
In addition to keeping the temperature stable, another way to keep the frequency of a crystal stable is to have an electrical circuit that changes depending on temperature and have that create something like an opposing curve, so you can add the two together and end up with a pretty stable frequency. Before you start asking how exactly, let me just remind you of the shoe with the stickiness on it.
<p>
In essence you have something like a resistor that changes resistance depending on temperature, it's a component called a thermistor, and that in turn affects a resonant circuit, also known as an Electronic Oscillator, or LC circuit, which in turn affects the circuit that is driving the crystal. These days most if not all of that is on a chip and you get a neat little package that you can plug into your radio to give it frequency stability and hopefully accuracy.
<p>
I did say I was going to talk about accuracy this week, but the doo-doo I stepped in put a swift halt to that. Besides, now I know that there is a thing called a thermistor, the second portmanteau I ever learned, together with Gerrymander, so there's that - oh, also, Tanzania, Eurasia and Oxbridge.
<p>
Back to Amateur Radio. The oven controlled crystal I mentioned last week, they exist in high-end measuring gear, not in the $26 TCXO I have installed in my radio. While I'm on the subject, you can also compensate for temperature with software, using either a purpose built micro-processor, or even the host processor that is using the crystal, but that gets into magic self-referencing voodoo pretty quickly.
<p>
And while I've been playing, Japan is finally being received here and I heard a station 18656km away during the week. Mind you, AA3GZ in Doylestown, Pensylvania, on the Atlantic Ocean side of the United States was putting out 100 Watts, so there's that.
<p>
I'll leave you with a thought that I hope to be able to answer next week.
<p>
If your radio has a crystal that determines what frequency it's tuned to, how do you use that to determine the accuracy of the frequency, more self-references, just because I can and besides, I'm a software developer and recursion is part of my make-up.
<p>
I'll give you a hint, it's not all to do with MHz.
<p>
I'm Onno VK6FLAB.
Listen:
What did you hear last week?
Foundations of Amateur Radio
<p>
Last week I spent a little time talking about the Weak Signal Propagation Reporters network, or WSPR, pronounced Whisper. You might remember that I set up my radio to receive these signals to see what I could learn. Turns out, I learnt quite a bit.
<p>
I left the software running for a week. During that time my station reported 456 signals received with a total of 54 stations in 27 call areas.
<p>
The longest distance 14,000 km, PC1JB in Veenendaal in the Netherlands who was using 1 watt.
<p>
The best performance based on km per watt is R0AGL in Siberia, 10,000 km, with 2 milliwatt.
<p>
Highest power heard, one station with 100 watts, but from a performance perspective, only just squeaks into the top 10 contacts. Typically stations used 5 watt or less.
<p>
My 10m quarter-wave vertical antenna was pretty good in hearing things across all bands. I heard stations across the frequency range, from 160m through to 10m.
<p>
It heard 1 station on 160m, VK7MF, using 5 watts, 3,000km away.
<p>
The most prolific band was 40m, accounting for 41% of the signals, 30m was pretty close at 35% and even 10m was respectable with 5% of signals heard on that band. Which brings me to a comment about propagation. The Solar Flux Index this week was pretty abysmal. It's been the lowest it's ever been, 66 and still I was able to hear signals across all HF bands.
<p>
Just think about that for a moment.
<p>
All the solar numbers say the bands are dead, all the listening in the world says the bands are dead, but using WSPR reveals that this isn't true, it's not even close to being true.
<p>
My station in a very high noise environment still heard signals across all bands.
<p>
Based on a visual comparison with other stations, signals were generated in all directions, but for my station, I didn't hear anything coming from the North East Quadrant, that's between North and East. It could be that the signals are being suppressed by the distortion in my antenna pattern, which might be caused by a metal gutter in that direction, or it might be that signals coming from that direction, mainly Japan and the United States, are too weak to be heard above the noise level at my station. I'm investigating that further, but that's for another day.
<p>
Speaking of other stations, in total during the same period as my station listening, there was a total of 6.9 million reports, representing 2490 listeners and 4463 transmitters. That means that I heard just over 1% of stations on my radio. Not bad given my meagre set-up and minimal configuration and installation.
<p>
On to things that I was attempting to learn about the performance of my radio. Every WSPR transmission includes the frequency and location information, which allows you to determine what the difference is between what frequency the other station reports and what frequency your radio sees.
<p>
Of course, there can be variation across both radios and to make things more interesting, this changes over time. This drift is likely to be distributed pretty evenly across all stations, but then I didn't hear all of them, so my results are not completely definitive, but overall the drift reports show a frequency drift of minus 3 to plus 2 Hertz. Slightly skewed down. That's not yet conclusive proof that my station is slightly off frequency, but it seems to indicate that my new crystal is slightly low. I'll be investigating that further.
<p>
And that neatly brings me to why I have been doing this.
<p>
You might not be surprised to learn that many things inside your radio are frequency controlled. Those frequencies come from a single central location, a master oscillator that in my radio vibrates at 22.625000 MHz. The crystal that does this is affected by temperature. When you transmit, the radio heats up and the frequency of the crystal changes slightly. Normally this isn't an issue, but if you're working on being on a particular frequency, especially on the 2m or 70cm band, then this starts to matter. If you leave your radio running for a few hours, things are likely to be more stable, since the temperature in your radio becomes more stable.
<p>
Another way to do this is to control the crystal temperature directly. You can insulate it, or heat it in a little oven, or a combination of both. This is a so-called Temperature Controlled External Oscillator, a TCXO. It's more stable and thus over time the frequency shouldn't change much.
<p>
In my case, the range is 5 Hertz and as I said, it's slightly skewed down.
<p>
The next step is to measure the actual frequency that my radio is tuned to. This will require a little more effort. I'll talk about that next week.
<p>
In the mean time, I'm doing some more analytics to compare how my noise-floor affects my station, how it compares to other stations across the same time-range and how little changes in volume, antenna and the like affect what results I get.
<p>
There is lots of data to digest, lots of knowledge buried among the stats and I'll be spending the coming weeks seeing if there are things here of a wider interest.
<p>
One thing's for sure, this is the simplest way you can measure and compare your station against a whole globe of other stations. Of course it doesn't actually get you on air to make noise, and that is the ultimate test of the success of a station.
<p>
I'm Onno VK6FLAB
Listen:
Hearing very weak signals
Foundations of Amateur Radio
<p>
This week I'm going to talk about a Digital Mode you can use with any Amateur License, or even without an Amateur License. You can set-up your radio, hook it to a computer and the Internet and after installing some software, you can join the Weak Signal Propagation Reporters.
<p>
So how do you start, what does it do and how can it help you?
<p>
First of all, WSPR, pronounced Whisper, is a way of encoding information and transmitting it across the spectrum. At the other end a radio receives that signal, sends it to a computer where a piece of software attempts to decode and then log it.
<p>
This Digital Mode, invented by Joe K1JT, is one of several modes that are gaining popularity across the Amateur Radio community because the beauty of this mode is that it's so unobtrusive that you're unlikely to actually hear it if you were to tune to a dedicated WSPR frequency.
<p>
If you want to find out what your station can hear, you can set yourself up as a dedicated receive-only station and report your findings to a central database where others can share your information and learn what propagation is like at that particular point in time.
<p>
Of course, it also means that you can use the same information to learn what propagation looks like in your neck of the woods with your radio and your antenna set-up.
<p>
There's even an option that allows you to have your radio automatically change frequency - known as band hopping - and listen for WSPR signals across the bands that you allocate.
<p>
If you like, you can go to the wsprnet.org website right now and do a search for my callsign, VK6FLAB and see what stations I've heard since I turned it on. Go on, have a look, I won't mind.
<p>
My station is set-up to do band hopping across all HF frequencies all day and night and during the grey-line it only listens to 80m, 40m, 15m and 10m, since those are the frequencies my license allows me to transmit on and I'm particularly interested how they work at sun-rise and sun-set.
<p>
You might have heard me before talking about how the noise at my home is atrocious. Nothing has changed, it's still abysmal, but WSPR signals are coming in and being decoded.
<p>
If you want to do this, you'll need a radio - any radio will work, a computer with a microphone socket and a way to pipe the audio from the radio into the computer, I'm using a 3.5mm male plug to 3.5mm male plug - you don't need a fancy audio interface, you're only listening. If you can connect an interface cable, your computer can also change frequency for you, but that's not needed to get started.
<p>
Make sure that you turn the volume right down before you plug anything in. Connecting a headphone output directly into a microphone input can blow up the port if you're not careful and WSPR doesn't need much in the way of volume. The software helps you get it set right, so read the manual before you start.
<p>
Once you've set-up your radio and your computer, you can watch the signals coming in on a waterfall display, a graphical representation of the audio and frequency that shows strong signals in red and no signal as blue. You'll find that turning up the volume too high will actually reduce the ability to hear signals.
<p>
I'm keen to learn what I can hear and how many stations my simple 10m vertical antenna can hear across the Amateur Radio spectrum.
<p>
I'd love to hear your weak signal stories and see what you can hear. As I said, it seems I'm becoming a short-wave listener after-all.
<p>
I'm Onno VK6FLAB
Listen:
Radio signals don't travel in straight lines
Foundations of Amateur Radio
<p>
The other day a friend of mine asked a really silly question.
<p>
How come when I point my YAGI at a direction for a station using the great circle, the signal is there but weak, but when I point it in a different direction, say 20 degrees away from the great circle, the signal improves?
<p>
Being a good little Amateur, I responded with the logical explanation.
<p>
Well, two things come to mind, one being that you're not pointing where you think you're pointing, that is, North on your antenna isn't North in reality, so when you point at the other station, it's not actually where you're pointing, and when you adjust, the antenna ends up in the correct direction.
<p>
Another explanation I came up with is that the pattern of their YAGI isn't what they expect. There might be local factors that influence the pattern, putting weird distortions into their foot-print and making for "interesting" nulls where there should be signal, and vice-versa.
<p>
That in turn started a whole conversation about directions and where stations are.
<p>
Leaving aside the difference between long-path and short-path, which I should probably talk about at some point, an antenna should get signal from the direction in which you point it, right?
<p>
So, what if I told you that the antenna was in fact pointing correctly and there were no distortions in the antenna pattern, what then?
<p>
Turns out that the Ionosphere isn't uniform - who'd have predicted that - in case you're wondering, that's a joke - the Ionosphere isn't uniform, it takes in many and varied influences, from the earth's magnetic field, to heating by the sun, to solar storms, coronal mass ejections, and any number of factors that we as a species are only just beginning to discover.
<p>
If you imagine for a moment a radio-wave coming up from your antenna, bouncing against the Ionosphere, back to earth, then bouncing back up, then doing the same thing again, you'll quickly understand that because the Ionosphere is variable, the height and angles at which this bouncing is occurring varies along the path.
<p>
But here's a shocker, who said that the signal had to bounce up and down vertically, what if the same variability of the Ionosphe height caused a signal to bounce in some other weird direction, like at an angle, or side-ways. Would the path of the signal from your station to the other end follow a great circle line?
<p>
Turns out that this silly question wasn't silly at all and I learned something unexpected, my radio signal isn't a straight line, something which I confess, did come as a surprise, but now, looking back, seems pretty obvious.
<p>
I love silly questions, they often turn into an opportunity to learn.
<p>
I'm Onno VK6FLAB
Listen:
What to pack for a Contest?
Foundations of Amateur Radio
<p>
In the past I've talked about what kind of station I have, how I tend to operate and what kind of tools I use in my day-to-day running of an Amateur Radio station. This week I want to take a closer look at what I do when I participate in a contest.
<p>
I remember fondly the first contest I ever set-up for, fondly as-in, "What was I thinking?"
<p>
Let me set the scene.
<p>
I'd previously been to a few stations that were participating in a contest. Some of those were in a club-shack, others were set-up portable in the field. For my first contest I was going to set-up my station in the field, so I needed to bring everything myself. Fortunately I was with friends, one with a camper-trailer, so I didn't need to bring a roof, or the kitchen sink, but I did bring pretty much everything else.
<p>
My list included tables, chairs, antennas, radios, headphones, connectors, soldering iron, power-boards, extension cables, logbooks for paper logging, pens, clipboards, two computers, four spare batteries, power supplies. It took hours of preparation, packing and not to forget, lugging, and when the contest was all done and dusted I noticed that while I brought everything, I didn't bring the right things and some things were missing.
<p>
For example, the little connector cable between the front face of my radio and the back of my radio was not packed, so I could only work with a long cable, which was subject to interference which I couldn't fix because I didn't have any ferrites. Other missing tools were a multi-meter, an antenna analyser and a dummy load, to name just the ones that come to mind today.
<p>
A wise man once told me that the more you camp, the less you bring.
<p>
Combined with my first contesting experience, that's become my motto.
<p>
Bring Less.
<p>
So last week, I packed much less and much more precise. My total packing list was:
<p>
A radio and a tuner, wire for wire antennas, crimp connectors and a crimper, a multi-meter and antenna analyser, a dummy load, barrel connectors and adapters from N to PL259, BNC and the like. A computer for logging and a CAT cable, a headset, a foot pedal, a notebook and pen.
<p>
That's it - other than a toothbrush and a sleeping bag and warm clothes.
<p>
As it was, my foot pedal didn't work, because there was a fault in the adapter cable and I've added fixing that to my list of to-do items. Which brings me to the next thing I learned.
<p>
It doesn't matter what you start with on your first contest. What matters is that you track it and then after the contest try to spend some time figuring out what worked and what didn't. If you update your list then over time it will become better and targeted to your specific circumstances.
<p>
When I do a contest mobile from my car, my packing list is similar, but not the same. I've not yet got it down to a fine art, but I'm getting better. One day I'll have the perfect kit, but then something unexpected is likely to happen and the perfect kit will change, again.
<p>
What is currently in your contesting list, what do you bring and what do you leave at home? What adventures did you have with your latest contest and what lessons could you share with others?
<p>
I'm Onno VK6FLAB
Listen:
Ladder Line is not Evil
Foundations of Amateur Radio
<p>
The way we connect our antenna to our radio depends on a number of different factors. If you've come through the ranks recently, like I have, it's probable that you've only ever considered using COAXIAL cable. It's a single conductor, surrounded by some type of insulator, which in turn is surrounded by a conductive shield, which is protected by another layer.
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There are variations where the shield has multiple layers, including layers of foil and braid, so-called quad-shield COAX, and there are variants that have several cores, sometimes two sets of COAX connected side-by-side and so on.
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In many ways, COAX is an invention of convenience, which has several compromises as a result, loss over distance, termination issues, twisting and deformation and others. It's compact, less susceptible to external interference, it's relatively easy to route to its destination and if you treat it well, it's easy to carry around, but it's not the only way you can feed an antenna.
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You may have come across the term Ladder Line or Twin-lead, or Twin-feed line. You may also have heard horror stories associated with this "ancient" - well at least in Amateur Radio Terms - technology. Essentially, Ladder Line is two conductors, side-by-side, evenly separated by spacers. It's in use all over the place. If you look up at your power-lines in the street, or the high-voltage lines on top of towers, you'll notice that those are essentially Ladder Line.
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You've no doubt been told that you need to keep Ladder Line away from everything, in order for it to work, but that's not actually what's needed. What's required is that both conductors are exposed to the same fields. This means that if you're running the Ladder Line through a metal window, you need to ensure that both lines get the same amount of exposure to any nearby metal, you might put a slight twist in the Ladder Line, or you might put it in the middle between two bits of conductor, like a metal window frame.
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You might also have been told that Ladder Line radiates. It does, but only if the antenna you're feeding isn't balanced, because what actually happens is that the two sides of the antenna don't cancel each other out and the difference is radiated by the Ladder Line. It's worse if the Ladder Line is some resonant length on the frequencies on which you're using the antenna, because it will receive the signal from your antenna and re-radiate that too.
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It really means that you need to pay attention, but the cost of that attention pales into insignificance, if you think of the benefits.
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You might recall that your radio is most happy when it's transmitting into a 50 Ohm load. One of the measurements associated with that is an SWR reading of 1:1. This has come to be interpreted as: "You need a 50 Ohm antenna in order for it to radiate." and that's not actually true.
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All antennas will radiate, and as long as they are at least half a wave length long, their efficiency will be about 90%. The problem isn't the antenna, it's how you feed the antenna. As I said earlier, if you're a relatively new amateur like me, you might have put one and one together and decided that you need to feed it with 50 Ohm COAX and that your antenna needs to be 50 Ohm. If you do that, it will work, but it's not the only way.
<p>
The reason you need to have a 50 Ohm feed-point to plug your COAX into, is because the COAX has a lot of loss if there is a feed-point mis-match. The higher the mis-match, the higher the loss. For example, using an 80m Dipole on 40m might mean an SWR of 65:1. This has about 80% loss on 100 feet of RG-8 COAX at 7 MHz. All you're doing is heating up COAX.
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However, if you were to feed it with 600 Ohm Ladder Line, the loss might only be around 3%. Before you start getting out the calculator to prove my maths wrong, this isn't about maths, it's about the difference between Ladder Line and COAX.
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COAX is wonderful as a tool, but Ladder Line should not be consigned to the annals of history, because in many, many situations it out-shines COAX. The combination of the thickness of the conductor and the separation width, determines its native impedance. There is lots of documentation online, including calculators on spacing and thickness, so you can build your own.
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I've seen lots of different types of spacers, from watering tubes cut to length holding the wire with cable-ties, to bits of Perspex, to cutting board plastic and others. The simplest and cheapest one I've seen to date was last weekend, made from two earth wires separated by strips of garden edging that comes in rolls. You cut off little strips, drill two holes, feed the wire through and if you're feeling that it needs permanency, glue them in place.
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Of course you can buy the stuff, but it's getting harder and harder to find at reasonable cost, so experiment a little.
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Ladder Line, it's not evil, it might surprise you and you will have another feather in your cap when you go out portable to set-up a field station.
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I'm Onno VK6FLAB
Listen:
Organisation around your shack
Foundations of Amateur Radio
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The art of keeping your station organised and accessible has much to do with choosing wisely which bits to keep and which bits to throw. That's part of the story, but there are other aspects of organisation that will assist you.
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Rolling up coax is a skill that you need to learn. The over and under method of coiling cable is by far the easiest way to ensure that your coax stays healthy and happy without kinks and other distortions.
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Once you've coiled your coax, many amateurs use electrical tape to hold the coil in place for storage. This can be helpful, since it means that you'll always have a handy supply of electrical tape on hand for when the need arises, but an alternative is to use Velcro cable wraps which attach semi-permanently to one end of the coax and can be wrapped onto itself to make a loop around the coiled coax.
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Making a water-proof connection, for temporary use can be as simple as covering it in electrical tape. This isn't ideal and not permanent and water inside coax is a guaranteed way to create problems that go well beyond the one time that it got wet, with rust and rot destroying the connector, then the conductors and then ultimately your radio. A better solution is to use either self-amalgamating tape, or plumbing tape to cover the join, followed by electrical tape and even cable ties to ensure that the tape stays in place.
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There are self-amalgamating dispensers that allow you to coat a connector in a sticky goo that also keeps water out, but getting it off at a later stage is guaranteed to make your hands black and sticky.
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If you're operating portable, then getting your wire into the air might be associated with throwing something into a tree to pull your antenna up. A fishing rod is a very helpful tool, complete with some fishing weights, to get the wire into a tree. Bring spare sinkers because you're going to lose some along the way.
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Storing a cable or stay kit is often a laborious affair with the rope getting tied up in knots throughout your kit with the next 30 minutes spent untangling the almighty spider-web that magically appeared inside your go-kit. A great way to prevent such an adventure is to invest in different size zip-lock bags. You can label the bag appropriately and see inside what's there, so if you have a few of them, you only need to grab the one you need and use different sizes for different purposes. Too small means they pop open and too large means you can't find what you need.
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Bring along some ratchet straps. They don't need to be 20m monsters, 2m is just fine, but bring a few. You'll be surprised how often they come in handy to tie down a radio, or a squid-pole, or strap a clipboard to something.
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A clipboard is a useful surface to write on, to keep your logs and if you get a clipboard box, you can store your electronic log keeping device and some pens in the same place.
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At one point I actually attached the head of my radio to my clipboard with some screws which made operating and logging even easier.
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No doubt you've got some tips of your own, so feel free to drop me a line and share.
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I'm Onno VK6FLAB
Listen:
A transistor radio curve-ball ...
Foundations of Amateur Radio
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Today I have a confession to make. Looking back it's clear that once your brain goes down a certain path, it's easier to follow the path than to find an alternative one. When I was growing up, above my bed, bolted to the wall were two brackets. On top of those brackets, secured with double-sided tape was a radio-cassette player. If you're unfamiliar with what an audio cassette is, don't worry, this is about the radio side of things and is from the days when Digital Music was not in wide use like it is today.
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I used this radio to listen to local stations, both on the AM and FM broadcast band, and I managed to even get to the beginning of the FM broadcast band where the police radio happened to be at the time in the country I was living.
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As years went by, that radio-cassette player was replaced with a radio tuner, then a combined amplifier tuner and I re-programmed it as I moved around the globe with new local stations filling up the quick select button memories.
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Over the last year or so it occurred to me that my latest device had been sitting inside a box in the garage for the better part of a decade and that the gap was filled by the radio in my car. I would drive somewhere and turn on the radio and listen to something interesting, or something boring, depending on what the airwaves brought to my antenna at the time.
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I started wanting to listen to the end of interviews, or rock along to some other happy tune when I got home, but I found the transition to be painful. I experimented with streaming radio, spent hours looking for software and currently the best I can do on that front is to have an App on my phone that streams a local radio station.
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You're likely by now doing one of two things. We'll get to the second one in a moment. The first one is probably going to be along the lines of "Yeah, so, what exactly has this got to do with Amateur Radio again?"
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If you're not thinking that, you might be thinking something that only occurred to me last week. "Why don't you use your Amateur Radio and tune that to a local broadcast station?"
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Indeed, why not?
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I'd never considered that even though my Yaesu FT-857d can tune from 100 KHz through to 470 MHz, covering most of the Amateur Bands, I'd never considered that it would also allow me to listen to a local broadcast station.
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It's not that I haven't actually tuned to those stations, or listened to the local Air Traffic Control frequencies, or the local Non Directional Beacons when they still existed, it's that those activities were in the context of Amateur Radio, along the lines of propagation, or interesting signals, not background music, or listening to an interview or a talk-back station.
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I've not yet gone to the trouble of pre-programming those stations, since my Amateur Radio is sensitive enough to pick up stations that my car cannot hear, but the list of frequencies that I'm tuning to during the day, using AM and FM is growing. Shame I can't get FM stereo from my Yaesu radio, perhaps that's something I should play with at some point.
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So, my second point is, "Duh, my Amateur Radio is also a radio, that you can listen to other broadcast stations with."
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Of course, it's a pretty pricey transistor radio, or short-wave radio, if you think of it like that, but if you've got it sitting next to you right now, it's simpler than making streaming radio work.
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I started this with paths travelled and I'll finish with that. When something like this happens, stop for a moment, celebrate the insight, share it with others and who knows what other things will bubble up.
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When was the last time your brain surprised you and what do you listen to that's not Amateur Radio? Who knows, I might become a short-wave listener yet!
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I'm Onno VK6FLAB
Listen:
Tropospheric Ducting explained
Foundations of Amateur Radio
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You've always been taught that VHF communications are line of sight and that the height of your antenna determines how far your 2m communication might go. So if I tell you that last week I spoke with a station that was 300 kilometres away on the 2m band you might be forgiven in thinking that I had managed to climb up most of the side of Mount Everest to around 7 kilometres so I could make my line-of-sight communications 300 kilometres away.
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I'll give you a hint. I was at my home, my house isn't on the side of Mount Everest and we were both using normal gear, nothing crazy, no amplifiers, no glitzy antennas, just the basics.
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So what's going on?
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There'ss a phenomenon called "Tropospheric Ducting" that comes and goes and if conditions are right, allows you to extend your line-of-sight communications to distances far beyond your imagination.
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So, what is this thing and how does it work?
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First of all, this is something related to the lowest part of the atmosphere, called the troposphere. It has nothing to do with the ionosphere which we know and love and use regularly to make long distance communications on the HF bands. The ionosphere starts somewhere about 60km up, the troposphere stops at about 12km.
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Tropospheric Ducting happens much lower down. At the most around 3km up, but normally between 500m to 1500m. In essence a Tropospheric Duct is a layer of warm air trapped between two layers of colder air that acts as a tunnel for radio signals. These kinds of layers aren't caused by "weather" as such, but by climate conditions such as weather fronts. Normally as you go up into the atmosphere, the temperature drops. The rate is around 6 degrees Centigrade per kilometre.
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Without going into the fascinating science behind it, think about it as a phenomenon where you'll find different types of layers of air over the top of each other, each with their own density and temperature. When the conditions are just right, you get a tunnelling effect that allows you to make some very long distance communications. There's reports of signals travelling over 4000km and if conditions are right, you might be able to hear such long-distance signals on your house-hold FM radio.
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One aspect that you might not have considered is that the thickness of the sandwiched warm layer determines which frequencies can travel along this so-called tunnel. If the thickness is 15m, you can expect to hear 11 GHz signals, 90m thickness gives you 400 MHz propagation and 180m thickness gives your 140 MHz signals a path to travel. If you manage to find a layer that's 430m thick, you might even manage to make contact using 29 MHz using a Tropospheric Duct.
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Now, you might be forgiven in thinking that this is all voo-doo and unpredictable, but it turns out that there are plenty of things that you can use to observe that conditions might be right. If you have local fog, or smog trapped over your station, you might be able to take advantage of this phenomenon. It's not that the smog or fog is causing the duct, it's that they happen to occur at the same time as the ducts are created.
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If you see a sharp layer in the sky, then turn on your radio and have a gander. I won't guarantee success, and you can look online for William Hepburn's World Wide Tropospheric Ducting Forecast, but you really don't need that to get started.
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Tropospheric Ducting happens all over the planet and it might be happening right now.
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I'm Onno VK6FLAB
Listen:
Storing your Amateur stuff ... everywhere.
Foundations of Amateur Radio
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There is so much stuff associated with Amateur Radio that your family might be forgiven in thinking that your hobby is all about being in the middle of a junk-yard surrounded by the carcasses of disassembled gear, components, failed projects, obsolete equipment and scraps of wire, solder and countless screws, resistors and other bits and pieces that are just too valuable to dispose of.
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During the week I was given an incentive to reorganise my work-shop. I set aside an hour to do it and unsurprisingly, armed with 20/20 hind-sight, it took a day to complete. The upshot of this activity is that I can now walk into my work-shop, something which I couldn't last week, and to top it off, I could actually find things.
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I confess that I've reorganised my work-shop several times over the years, but each time I find that it returns to its natural state of junk everywhere. I have noticed that this state is taking longer and longer to achieve, which means that I am improving things, but not quite as well as I would like.
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The biggest improvement I found last time around was to install shelving. I also used cardboard boxes to put stuff into, but that turned out to be a mixed blessing, tidy, but unusable, since I had to keep stacking and un-stacking boxes to see what was inside and writing on the outside only helped if the list of what was in the box was complete, which I'm sure you know, is never ever the case.
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This week I made an incremental change. I have purchased a whole slew of transparent plastic boxes, about the size of a shoe box each, with lid, stackable and big enough for most of the things I need to store.
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I've arranged the boxes along several shelves, stacked two high, so you only ever have to lift one box if you need to get to the bottom one.
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When ever I go into a bottom box, I move it to the top, so over time the most used boxes will be on top and the ones I don't use often will be on the bottom.
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Now I have a box with Velcro straps, one with cable ties, one with electrical tape, one with self-tapping screws, one with audio connectors and so-on.
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Time will tell if this helps.
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You might recall in the past that I've also got a stack of fishing boxes. Not a whole tackle box, just a single layer box with square compartments, removable dividers, just large enough for about 4 PL259 connectors in each. They're also transparent and stackable.
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Each compartment has some unique component. Red Anderson Power-Pole shells in one, Black in the next, Green, Purple, Yellow etc, each in their own little space. The connector innards are in another compartment, the joiners in another, BNC male connectors in another, and so-on.
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I've seen similar attempts at organisation using glass jam jars, but in my experience they don't stack well, are never uniform, unless you have 100 identical jars and are not compatible with concrete floors and gravity.
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I'm sure that I've missed some salient storage advice, so feel free to drop me a line and share your experiences.
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I'm Onno VK6FLAB
Listen:
Amateur Radio Regulation and Enforcement in Australia is Broken
Foundations of Amateur Radio
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The other day a fellow Amateur was relating their experience in the hobby. They spoke of interference, jamming, breaking in over the top of contacts and generally being hounded by special people who think it's their purpose in life to make life miserable for others.
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I have spoken in the past about similar experiences that I had with individuals jamming a weekly net that I've been hosting for new and returning hams, and occasions when I've been on-air with a special callsign with an individual yelling "pirate" at the top of their lungs in an attempt to get me off a particular band, even though I was operating in compliance with the license conditions.
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I've personally made complaints to the regulator about these occurrences, who then decided that being interfered with for over a year was something that the repeater owner should complain about. When they complained, they were told that there was not enough evidence, or some such excuse, I forget exactly the details, but the problem was never investigated or regulated.
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I contacted the regulator to advise them of interference of our National Broadcaster on a particular frequency, on a particular stretch of road and their response was that it wasn't their problem to fix - even though the Australian Communications and Media Authority is specifically the spectrum regulator. One particularly funny, though not in a hi-hi kind of way was when I was speaking with an investigator who asked me how I knew about interference. I explained that I was a licensed Amateur. His response was: "I'm a Professional". I can still hear the capital "P", years later.
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Compare that to complaints being raised about my use of a club call-sign, or the publication of my podcast on-line, or the inclusion of an audio stinger in the local news I produce, or the inclusion of a flea-market segment in the same news, or a podcast I made about the use of an Iambic Key by Foundation Licensees.
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In each of those occasions either the regulator or the peak representative body of Amateur Radio in Australia, the Wireless Institute, or both, jumped in feet first, making pronouncements, issuing decrees or directives without ever actually contacting the person about whom the complaint was actually about.
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It seems that there must be a special hand-shake in order for your complaint to be taken seriously, that, or they're both running scared because I venture to make an opinion publicly. No, it can't be that, we have freedom of speech in this country - right?
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Anyone?
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I'm Onno VK6FLAB
Listen:
Which antenna should I get first?
Foundations of Amateur Radio
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The other day I was asked about what antenna should you get as your first one. This question is pretty simple, but the answer is likely much less so.
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You might recall that I've pointed out that we can prove you physically cannot build the ideal antenna, so by definition all antennas are compromises.
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You might also find yourself being bamboozled by claims about how an antenna is the perfect match across all or many frequencies. The same is true for a dummy load where the purpose is not to radiate at all.
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With that in mind and armed with a healthy dose of scepticism, you can now go hunting for the answer.
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On my journey through this minefield of mysticism I went from a self built wire vertical on a squid pole with a 16 radial ground plane and an electronic antenna coupler, through a set of purchased single band verticals, a wire dipole, a wire delta loop, a Buddi-pole, a magnetic loop, a multi-tap vertical, and many others along the way.
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Some of those antennas were bought, others were built, several were given to me and some have been loaned by fellow amateurs.
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I should mention that the antennas I named were all for HF frequencies. On VHF and UHF, 2 m and 70 cm, the list consists of four antennas, I started with a simple vertical and in my car I use that almost exclusively. I also have two larger verticals at home, depending on what I'm doing I'll swap between them but for the past year I've had a 10 m vertical which also happens to be resonant on 2 m, so I can swap between HF and 2 m without climbing on a ladder.
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Building an antenna can be very rewarding but also very frustrating. Similarly, buying an antenna is no guarantee for success.
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This means that every environment is different and many combinations of antenna and location are doomed before you start.
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Essentially you have to start a process to find what works for you and your environment, a fixed location, or a car, portable, mobile or something else, in my limited experience there really isn't a substitute for trial and error.
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That being said, getting your hands on a balun and some wire is a good place to start. If you're looking for something that takes up less space, a vertical is often another way to get going.
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Currently in my car I use a multi-tap vertical. At home I'm playing with a 10 m vertical and a magnetic loop. When I set up portable on my own I'll use my squid pole vertical and if I'm with others I'll help string up as much wire as we can. At my local radio club I'll use one of several Yagi antennas and if I'm at a friend's place I'll use whatever they have plugged into their radio.
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This confusing mismatch of antennas reflects about six years of experimentation and I've not even mentioned the pile of failures sitting in the corner of my shack.
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Two more comments. Getting or borrowing an antenna analyser is a good idea and the amount of money you spend on an antenna is no indication of success.
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That's not really an answer, but it's the best I have.
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I'm Onno VK6FLAB
Listen:
Amateur Radio is about Experimenting and Trying!
Foundations of Amateur Radio
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The other day I was browsing through the Amateur Radio Syllabus for Foundation Licensees, as you do, you know, when you're bored out of your mind, or in my case, looking for a topic to talk about.
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So, I came across this interesting point, if you want to look it up, point 2.2 of the Foundation Syllabus. It states that in order to attain your Foundation License in Australia you must: "Recall that an Amateur Licence primarily authorises the operation of an Amateur station for self-training in radio communications, inter-communications between Amateurs and technical investigations into radio communications."
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You might hear that and think, ok, so what's your point?
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Simple really. As an Amateur Radio community we have come to collectively understand that in order for you to do anything in the realm of building or research, you need to hold more responsibility and that if you're on the so-called bottom rung of Amateur-dom, you really are only a button twiddler, appliance operator and not much of an Amateur at all.
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It's funny really, since the Amateurs I know and consider to be my friends and peers, exist across the wide spectrum, from being licensed last week, through last year, through last decade onto before I was born, more than half a century ago, these Amateurs have one thing in common - curiosity.
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They like to explore, to investigate, to understand, to learn and to try stuff. Many of these Amateurs have a Foundation License like I do and their skill in exploring has very little to do with their level of license and everything to do with their approach and attitude.
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I know that I can just go about my business and ignore the noisy minority who continue to be derisive towards lesser Amateurs, but I think it's important to highlight that my personal experience does not match their vocal opposition towards those who hold different opinions, find different things interesting, bring different approaches and attitudes or continue to be excited by this hobby.
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I know that I often point out this element of nay-sayers, but I'd like to also point out that while they make noise, a much larger group of Amateurs continues to play and explore.
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A couple of years ago, when the ink on my license wasn't even dry, I was dragged, almost kicking and screaming, to a national Amateur Conference by a fellow Amateur and good friend. I resisted, but his insistence saw me pack my bags and head over to meet a group of people who share this amazing thrill that I experience with Amateur Radio on a daily basis.
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I'm immensely grateful for my friend and his badgering, and want to point out that if you find yourself surrounded by those who continue to tell you that you need to upgrade, that what you're doing has been done and failed, that what you're playing with isn't interesting, that what you're doing is wrong. If you find yourself in that place, then I urge you to find new friends in Amateur Radio, because we're not all like that, in fact, I'm pretty sure, most of us are not like that.
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It's just that the know-it-alls are good at telling you so and the quiet achievers just get on with it.
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Find a friend, explore an idea, try something new, visit a new club, or go on an adventure.
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Amateur Radio is and should be fun and if it isn't you're looking in the wrong places.
<p>
I'm Onno VK6FLAB
Listen:
How does PSK or Phase Shift Keying actually work?
Foundations of Amateur Radio
<p>
Previously I've explained how Radio-teletype or RTTY works from a technical perspective. If you recall, it uses a technique called Frequency Shift Keying, or FSK to encode digital information. It does this by transmitting a carrier across two alternating frequencies, allocating one as a SPACE and the other as a MARK, or as a binary 0 and a binary 1.
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There are several other ways of encoding information and today I'm going to look at Phase Shift Keying, or PSK, which I find humorous, because Phase is spelled with a P, but it sounds like an F, which links the FSK and PSK together, but then I've always had a strange sense of humour.
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Imagine if you will a sine wave. It's the one you learned in high-school, nothing sophisticated about it, just keeps going up and down over time. Now imagine another one. Also going up and down over time. If these two sine waves are synchronised, going up and down at the same time, the difference between them is 0.
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If one of the sine waves is going up, while the other is going down, then the difference between them is 1.
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That is enough to give you a binary 0 and a binary 1. One of the sine waves is a carrier, so it's transmitted continuously, and the other is changed depending on whether you're sending a 0 or a 1.
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These two sine waves are said to be "in-phase" when they're both going up and down at the same time, and "out of phase" when they're going in opposite directions. This is how Phase Shift Keying works. And the simple example I gave is known as BPSK, or Binary Phase-Shift Keying.
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There are countless variations on this. For example, you don't need to have them going in completely 180 degrees opposite directions, you could go only 90 degrees, or even 45 degrees, which would allow you to encode more information across a shorter time span at the cost of less accurate decoding at the other end.
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You could play with the carrier and instead have the signal be compared to itself, making it more robust in some circumstances, or you could have multiple of these signals happening at the same time.
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You could change the amplitude of the carrier and allocate specific byte values to each combination. For example, one variation, an encoding method called "16-QAM" allows you to create 16 different signals, which equates to sending 4 bits at a time.
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Each of these have different advantages and disadvantages, trade-offs between speed, reliability, error detection, impact of polarisation changes in the ionosphere, energy efficiency, etc.
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You might be surprised to learn that these techniques are not only used inside Amateur Radio and PSK31, they're also used in Wi-Fi, Bluetooth, Ethernet, RFID and countless other places, like remote controls, hard-drives, tape recorders, satellite communications, mobile telephony, etc.
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If you get hooked, there's lots of maths that you can associate with all of this - if that floats your boat, but you don't need any maths to grasp how it works.
<p>
Phase Shift Keying, one of the many Digital Modes that make our world go round.
<p>
I'm Onno VK6FLAB
Listen:
How does RTTY work?
Foundations of Amateur Radio
<p>
The continued discussion in our community about Digital Modes got me thinking about what a Digital Mode actually is. At the most fundamental level, it's about encoding information into discrete chunks to exchange information. Morse Code is an example of a Digital Mode, made up from combinations of dits and dahs.
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If you change frequency whilst sending dits and dah's you invented RTTY or Radio-teletype. There are two frequencies involved, 170 Hz apart, where the lower frequency is the SPACE frequency and the upper frequency is the MARK frequency. If someone gives you a RTTY frequency, they're talking about the upper frequency.
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Instead of using Morse Code to send messages, RTTY uses 32 different codes, 5 bits, to exchange information. This isn't enough for the entire alphabet, with digits and punctuation, so two of the codes are used to swap between Letters and Numbers.
<p>
Some radios can change frequency between the lower SPACE and upper MARK frequencies in a single transmission. This way of transmitting is called FSK, or Frequency Shift Keying. It's a lot like moving the VFO around whilst keying a Morse-key. Not something you'd do manually, since in Amateur Radio, this is generally happening 45 times a second.
<p>
If your radio can't do the frequency shifting, then another way is to use Audio Frequency Shift Keying of AFSK, where instead of changing the frequency, you change an audio tone by 170 Hz. Without getting technical about how this works, if you've ever listened to Morse Code with a radio, you'll have noticed that as you change frequency, the sound changes. If you were to change the frequency of your radio by 170 Hz, the sound would also change by 170 Hz.
<p>
So with that in mind, if you were to change the sound by 170 Hz, the receiver wouldn't care if you were changing the transmit frequency or the audio frequency, since it both sounds identical at the other end.
<p>
Most of the time a computer is generating two tones, a tone for the SPACE, or lower frequency and a tone for the MARK or the upper frequency. It comes out of the speaker of the computer, which you feed into the microphone of the radio and your radio then generates a normal SSB signal that is experienced by the listener at the other end as a Radio-teletype.
<p>
Pretty nifty and if you understand this, then most of the other Digital Modes in use today use similar methods.
<p>
I'm Onno VK6FLAB
Listen:
Qualifications for using a Digital Mode
Foundations of Amateur Radio
<p>
Having a Digital Mode in your shack appears to be a special privilege, at least in some parts of the world. If you'd like to learn all there is to do with using a Digital Mode you need to pay attention and I'll share the secret, it won't take long.
<p>
If you want to distinguish yourself as a Digital Mode Diva, you need to know that Morse, RTTY, FSK and PSK are digital modes and you must also remember that the bandwidth of a data transmission is dependent on speed and mode.
<p>
At this point you've covered all the syllabus requirements for holding a Standard License in Australia in relation to operating a Digital Mode.
<p>
If you want to climb the Mountain of Digital Mode Magic, you need to remember two acronyms, FEC or Forward Error Correction and ARQ or Automatic Repeat Request. You also need to remember four numbers, 31 Hz for PSK31, 250 Hz for RTTY, 730 Hz for Packet Radio and 300 Hz for FSK. And if you want to get really fancy, I should point out that there are several versions of each of these modes and different ways to implement them, so those numbers will change depending on who's teaching you.
<p>
If I go on to tell you that a Terminal Node Controller or TNC is a black box with two audio leads, one for the microphone and one for the speaker and that you plug those into the appropriate sockets on your radio, you know all that is required to hold an Advanced Certificate in Australia for using a Digital Mode.
<p>
If you don't want to blow up your radio, then you should also remember that there is a thing called Duty Cycle that will come to haunt you if you get it wrong.
<p>
That's it, now you know everything there is to know about using Digital Modes.
<p>
Actually, I'm lying. When you say the letter A on air you use the word Alpha. You're sending extra information so the other end has a better chance of understanding what you said. That's Forward Error Correction.
<p>
And when you say the same thing repeatedly, like saying CQ, CQ, CQ, if you don't get an acknowledgement from the other end, that's Automatic Repeat Request.
<p>
Now you really do know all there is to know about Digital Modes according to the syllabus for both Standard and Advanced Licenses in Australia.
<p>
I'm Onno VK6FLAB
Listen:
Mechanical Filters
Foundations of Amateur Radio
<p>
The other day a whole new world opened up to me when I came across the idea that Voltage is the same as Force and Current is the same as Velocity. It all came about when I installed two mechanical filters into my radio. You heard that right, in my shiny solid-state radio, I added moving parts!
<p>
The purpose of this was to improve the way the radio ignores unwanted signals and as a result has an easier time hearing what it is you really care about. The radio already has filters built-in, but mechanical filters offer a cleaner output with less distortion across a wider range of temperatures. Another way is to say that - mechanical filters have a much higher Q.
<p>
Think of a pendulum swinging through oil, it's losing lots of energy for every swing and has a low Q. The same pendulum swinging through air retains most of its energy and has a high Q. The same is true for mechanical filters, less energy loss, better reproduction, better outcome for the things you want to keep and hear.
<p>
So how does this then work?
<p>
Turns out that our electrical theory with inductors, capacitors and resistors have mechanical equivalents, specifically mass, stiffness and damping. As I said when I started, Voltage is Force and Current is Velocity.
<p>
It turns out that all the maths we use to design electrical filters can also be used to design mechanical filters and 1946 Robert Adler from Zenith did exactly that. This worked so well that in 1952 the Collins Radio Company started manufacturing them and today we still use them in many different radios.
<p>
As an aside, you might be surprised to learn that the first filter that Robert Adler invented in 1946 was for a 455 kHz filter, which I could technically still use in my radio today, since the same Intermediate Frequency or IF is used.
<p>
The mechanical filter - vibrating bits of metal - resonate with specific frequencies, much like a tuning fork does, but your radio deals with electrons, not movement, so the electrical signal is first converted into movement by a piezoelectric transducer, a piece of material that distorts when you apply an electrical field and when you use it in reverse, distortion creates an electrical field.
<p>
So, you have a box with a wire at one end and a wire at the other and in between are two transducers and a bunch of mechanical resonators, much like a string of pearls on a necklace.
<p>
I mentioned earlier that mechanical filters have a much higher Q. An electrical Q might range between 100 and 500, the mechanical Q in 1946 using steel was several thousand and in today's filters using Nickel-Iron alloys, a Q of 10,000 to 25,000 can be achieved.
<p>
Without going into the maths, what is this Q really describing, other than the pendulum in oil and mechanical losses?
<p>
One way to explain Q is to say that it describes the "goodness" of a resonant circuit, the higher the Q, the better the circuit. In our case, "goodness" means that it resonates better where we want it to and not where we don't want it to.
<p>
Before you start wondering, why the letter "Q"? Turns out all the others were taken when K.S. Johnson was looking for a letter to describe the attributes of coils in 1920. Today we think of "Q" as Quality, but that's the cart before the horse.
<p>
Anyway, back to Amateur Radio. If you look at a theoretical filter, you'll see a lovely curve that lets through the bits you care about and ignores the bits you don't like, but when you then start looking at the real world where damping and resistance come into play, you'll soon learn that there are all manner of ugly spikes on this lovely curve.
<p>
A typical tuned electrical circuit will have artefacts, or distortions along the way, dipping down, instead of staying straight, or having an ugly peak when it should be smooth. This in turn results in something that you can hear, distorted audio where low frequencies are under or over represented and strange distortions occurring along the audio range.
<p>
It also means that adjacent signals, the ones you're trying to ignore get caught up in this same distortion and you'll hear some of those when you don't want them.
<p>
So when I say that a mechanical filter offers a higher "Q", it means a whole lot less distortion and a better representation of what's going on. As an aside, in transmit, a mechanical filter will also help contain the energy coming from your signal and transmit it where it's needed, rather than waste it where it's not helpful. As a QRP station, every little bit helps.
<p>
I just love this hobby, every turn is another surprise.
<p>
I'm Onno VK6FLAB
Listen:
Contesting Protests
Foundations of Amateur Radio
<p>
For the most part of my Amateur Radio life I've been an active contester. I have spoken about why I love contesting and why I think it's an important aspect of this amazing hobby. Today I want to talk about how contests are run, specifically how complaints are handled and how we could improve.
<p>
I must at this time acknowledge that organisers are volunteers, just like many other Amateurs, giving of their free time, in this case, to manage and score a contest. Like much volunteering it's an invisible, sometimes thank-less and unenviable task, often akin to herding cats.
<p>
To set the scene, a contest is an organised activity run by one or more people or groups that has a published set of rules, a set of aims and objectives as well as the mechanics of things like on-air conduct, point scoring, etc.
<p>
A contester who decides to participate in a contest is expected to read the rules, abide by them and conduct themselves in an appropriate manner, that is, keep accurate logs, follow the log submission rules, etc.
<p>
What happens after the logs have been submitted to the organiser is rarely spoken about. There is an assumption that the results are published, that complaints are handled fairly and in a timely fashion and that the outcomes are fair for all participants.
<p>
In my experience, it's understood that if the rules don't specifically exclude a particular event, like say, using a Satellite contact during a VHF contest, those are fair game. Of course the response to such a thing is to update the rules to exclude that interpretation for the next contest.
<p>
So, there are rules for the contesters, but are there rules for the organisers? What happens if they don't do their part? What process exists then? What if the results take over a year to be published, or you witnessed cheating, or you submit a log that has a score that differs from the results? If you bring that to the attention of the organisers, what is a reasonable response and how would you expect the issue to be resolved?
<p>
In the past, any suggestion that there could be a place for a standard set of rules for organisers has been, in my experience, ignored or ridiculed with the notion that "We're all Amateurs here, stop taking things so seriously." In my opinion, that's not a reasonable response and it makes for uncomfortable interactions between contesters and organisers who are attempting to resolve a dispute in a civil way.
<p>
In sailing, where the participants are amateurs, as in non-professional sailors, contesting is alive and well. Most weekends see a sailing race on a local water and protests are common. A standardised set of rules exist to handle disputes in a formal manner and raising a protest flag is the beginning of a set of steps that ends up with a ruling.
<p>
In the case of contests in the Amateur Radio field, no such thing happens.
<p>
As an example, I have personally raised a protest with a contesting organiser and have spent the past months attempting to get the results updated to reflect my actual score. I'm patient and persistent, I document every step, but ultimately I'm at the mercy of the organiser. Their decision to handle my protest is entirely arbitrary. In my opinion, this is not how contesting should work. It should be a fair contest between stations to apply the rules and come to a score.
<p>
I've purposefully not named the contest or the organisers, since this is not specific to my protest. This is an issue that affects contests in Amateur Radio everywhere.
<p>
What about looking at the sailing community and learning about their protest procedures? Are there contests that you participate in that have a formal complaints process and how well does it actually work? Have you ever had a contest protest that needed adjudicating and how did it work out?
<p>
I'm Onno VK6FLAB
Listen:
Our Amateur License System is Obsolete
Foundations of Amateur Radio
<p>
Recently I made a point of coming up with three different names for License Classes in Australia. I proposed Low Power, Medium Power and High Power and then went on to suggest that this could also be a mechanism to update the framework that is Amateur Licensing in Australia. As it turns out, I'm told that this idea is mostly already active in the United Kingdom.
<p>
My idea started as a response to an increasing clamour for more privileges for Foundation Licenses. These calls include demands for digital modes and more power. I understand this demand, though I don't particularly share it.
<p>
I think that licenses evolve and the world in which they operate changes and that digital modes are an example of that.
<p>
I have a much bigger problem with the way that licensees are using their level of license to look down on those who have "only" achieved their Foundation or Standard call. I have personally been told that I should get rid of my silly license and upgrade and it's unusual to meet a new Amateur who doesn't straight off the bat ask me why I haven't upgraded yet.
<p>
I've seen the same behaviour toward Standard licensees and I think it's a fundamentally wrong attitude and approach to have.
<p>
In my opinion this is a hobby for participants to do what they want to do within the constraints that they have. For some that means getting a higher level of responsibility, for others it means spending time doing deep learning and investigating the boundaries of their achievement.
<p>
The notion that there are different levels of license is completely arbitrary and the idea that some are better than others is ludicrous in my opinion. Just because I have a Foundation License, doesn't mean that I am ignorant and just because others have an Advanced License, doesn't make them all-knowing or expert.
<p>
If that wasn't enough, the boundaries between license classes are completely subjective, drawn from historic demarcations between VHF and HF, between Build and Buy and between Morse-Code and Not. These lines are getting so silly that they have become meaningless, to the point of absurdity.
<p>
If I as a Foundation License holder can go to a shop and buy a Software Defined Radio, then update the software on that radio by using my skills as a programmer, I have fundamentally changed the way the radio operates, even-though I didn't once touch a soldering iron, or open the case. Our regulations have nothing to say on the subject, nor is there any sane way to police such an activity and nor should there be - this is an experimental hobby after-all.
<p>
If I buy a radio in kit form and get it shipped to me, put it all together and turn it on, did I build something, or buy a commercially available radio? Where's the line between building and buying commercially available and what at the end of the day does it really matter?
<p>
What is so special about the 20m band that prevents me as a mere Foundation Licensee to access that band and what is so amazing about digital modes that make it that I'm not allowed to use it, even though all digital modes are really just analogue audio and there is no certification, training or assessment related to digital modes for any class of license?
<p>
My point is that the current licensing system is in my opinion obsolete, it's broken and the persistent baying from the sidelines by Amateurs who think that I'm demanding more privileges is getting tiresome. It's ludicrous to think that we should remain back in the 1970's, when Novice Licenses were introduced, perhaps while we're at it, should we go back to a spark-gap transmitter too?
<p>
The idea that your enjoyment in the hobby is affected by my privileges is absurd to the level of being offensive and if you're threatened by my participation in the hobby, it seems to me that I must be making valid points.
<p>
I don't want more privileges. I'm happy with what I have. What I want to do is make this hobby better, make it relevant, make it useful, make it accessible and make it stronger.
<p>
That's why I proposed to make three license classes, Low Power, Medium Power and High Power, to make some common-sense where none currently appears to exist.
<p>
I'm Onno VK6FLAB
Listen:
Quick Fixes and Maintenance
Foundations of Amateur Radio
<p>
There is a time for everything. Mostly when it's most inconvenient, like in the middle of a rare contact, or while you're running a pile-up like you have never done before, or while you're getting a multiplier during a contest.
<p>
For two years I've been using an antenna on my car that on occasion has the ability to remind you of it's presence. In this case, there is a lead, a so-called wander lead, that runs from the base of the antenna to one of the various connectors that are spaced along the length of the antenna. In case you're wondering, it's an Outbacker antenna and it's the first antenna that actually worked on my car.
<p>
This lead has two banana-plugs on it, and those are connected to the lead with little screws which have an uncanny ability to come loose when you least desire it.
<p>
This ability of an item connected to your radio to make itself known to you is not limited to my wander-lead. I've seen the same behaviour on microphone connectors, interface adapters, baluns, speaker leads, power leads and the like.
<p>
Often you cobble together a quick fix and off you go again, doing what you were doing. Only the quick fix turns into "the fix" and nothing is ever actually fixed. I've been to many shacks where a quick fix has been applied that lasted days, weeks, months, sometimes even years, but at some point it will fail again, perhaps with disastrous results, like letting the magic black smoke out of your radio - and if you're not sure what I'm talking about, ask a friend, but the smell is memorable and often there is a matching invoice to pay.
<p>
During the week I did something novel. I remembered the last quick fix I did and instead of thinking: "I should do something about that", I actually went to my car, got out the antenna, pulled off the wander lead and actually fixed it, that is, got out a proper screw driver and actually tightened the screws. Mind you, as I'm thinking about it now, I have started to think about if I should solder the lead and remove the screws from the whole thing. I'll let you know how I go.
<p>
The point I'm making, badly perhaps, is that the hobby we are engaged in, Amateur Radio, is about more than making contacts and building stuff, it's also about doing maintenance and thinking about how to make your station safer, more reliable, more usable and fixing those niggling little things that will come and bite you at some point in the future.
<p>
Before I go, I should anticipate some responses which will be along the lines of: "Well, it was a quick fix, but it lasted for years." - good for you, you're a better fixer than I am. For the rest of us, have a good look at your station and think about some quick fixes you've applied.
<p>
I know I'd prefer to complete the QSO with that rare DX station, rather than have them vanish and later learn that their microphone packed up mid-contact.
<p>
I'm Onno VK6FLAB
Listen:
What's in a name?
Foundations of Amateur Radio
<p>
For a long time I've struggled with the way we differentiate between the different license classes in Amateur Radio. In Australia, the three levels of license are Foundation, Standard and Advanced. In the United States, they're called the Technician, General and Extra. In the United Kingdom they're called Foundation, Intermediate and Full.
<p>
These naming conventions convey that more and more is gained as you progress though the ranks, but they also convey that you are incomplete if you're not at the top of the food chain with an Advanced, Extra or Full license.
<p>
This naming convention is not universal. The license classes in the Netherlands are called the N or Novice Class and F Class, but generally they're referred to as the N and F classes and in Germany they're called Class A and Class E.
<p>
Of course if you're making a complaint about what something is called then coming up with a new name is one of the first things that you'll be asked and that has stopped me from even beginning to make this observation out loud, let alone spend some time talking about it.
<p>
Today I have a response to the question: "Well, if you don't like what it's called, what would YOU call it?"
<p>
Here's what I came up with, if we're staying with three license classes, the three names I'd adopt are Low Power, Medium Power and High Power. The names are chosen to distinguish the power levels associated with the license which then also allows for another radical idea.
<p>
What if everyone had the exact same privileges and the only difference between the licenses was how much power you could use?
<p>
This in turn would require a person who moves from one power level to the next to learn specific skills. For example, RF safety with Low Power is completely different from High Power. Antenna efficiency has a completely different impact on a high power radio, than it does on a low power radio.
<p>
Interacting with high voltages doesn't happen with low power but you can bet your RF burn that it happens with high power.
<p>
EMR, or Electro Magnetic Radiation issues were the single largest hindrance to introducing more than 400 Watts into Amateur Radio in Australia. What if getting a High Power License came with a built-in EMR module and that the energy was built-into the licence system?
<p>
If all licenses were the same, except for the power output, it would mean that all Amateurs could experiment with new modes and invent new things and the only hindrance to such experimentation would be the imagination of the person using the radio.
<p>
We have artificial boundaries between the various classes of license which bear no relation to reality. In my opinion the boundaries hinder the progress of an amateur and external factors such as the changing of the solar cycle impact different license classes in different ways depending on when they got their license.
<p>
Skills that are gained could be gathered as points or modules and could incrementally allow the progression to higher power.
<p>
Of course, 100 Watts on 160m does not have the same impact from an EMR perspective as 100 Watts on 10 GHz, but I'm not advocating that the Low Power license is limited to 10 Watts across all bands, nor am I saying that a Medium Power License should have 100 Watts on every band. But there's no reason that the power level cannot be proportional to the amount of energy involved, rather than a fixed power output at the transmitter.
<p>
For my money, lets ditch this Foundation, Standard and Advanced system and move to Low Power, Medium Power and High Power.
<p>
Who's with me?
<p>
I'm Onno VK6FLAB
Listen:
Mobile experiments with high power.
Foundations of Amateur Radio
<p>
A little while ago I had the chance to use a mobile radio with high power. I used it to learn about the coverage of our local repeater, but also to hear what the effects were when two local radios were both using the same repeater and high power at the same time.
<p>
I made all manner of observations and wondered how much of what I observed was real and how much was a case of me adding two and two together and coming up with five. Immediately after I made those observations I received emails from around the globe explaining in great detail what was going on.
<p>
Suffice to say that there was some disagreement among the emails, but overall they lead to a few new things that I'd not considered.
<p>
One comment was that the two radios, not quite side-by-side, but in two cars nearby was similar to the operating environment of a repeater, that is a receiver and a transmitter sitting in close proximity. Initially I didn't cotton on to the analogy and it took several readings to understand, but the outcome is that, as I suspected, the receiver is being overloaded by a local transmitter which is putting out a big signal that is overwhelming the electronics in the receiver, something that a repeater deals with every time you key it up. The short version of this is called de-sensing. I'm still reading about how it exactly works on the inside, something for another day.
<p>
In a repeater the issue is dealt with by filtering the outgoing signal and filtering the incoming signal, making sure that only the desired information makes it to where it needs to go. Two random radios bolted to two cars don't have any such filtering and no way to reject the unwanted signals. Adding filters to both cars might fix the issue, but then we weren't trying to fix anything, just to learn what was going on.
<p>
Another thing I learnt was that FM receivers don't need an AGC, since the volume of a signal is related to how much it deviates from the central signal, not how much signal there is, which is why the microphone gain setting on your radio determines the volume, not the level of power. To be clear, enough of your signal needs to get to the other end for it to work, but after that, you're just wasting electrons. If you need a visual for that in FM the height of the signal doesn't matter once it's high enough, the wobble determines how much volume there is. In AM, there is no wobble, the height determines the volume.
<p>
Incidentally, if not enough of your signal gets to the other end, then your weak signal might be overtaken by another signal and the so-called "FM capture effect" happens, where the low signal gets effectively rejected in favour of the higher one.
<p>
Interestingly Amateur Radios can have an FM AGC which can be used to determine the signal strength, which makes your S-meter behave more like it does on HF, but if you recall, an S-meter is really a guess-o-meter since every manufacturer has their own "standard" and two radios are unlikely to experience the same S-level for the same signal. Don't misunderstand, I'm not maligning the S-meter, just pointing out that your S-5 and my S-5 are unlikely to be the same.
<p>
So, the more I peel away from my little mobile experiment, the more I unearth in the wake of the experiment. Such is the joy of Amateur Radio. Be curious, investigate and learn.
<p>
I'm Onno VK6FLAB
Listen:
Magic and Curiosity in Amateur Radio
Foundations of Amateur Radio
<p>
You know you've been at something for a while if you come across a topic that you want to dig into and discover that you already covered it in great detail a year ago. For me that topic was the "FM capture effect", which I covered in great detail a while back - the research says: "This happens, we know it happens, it happens under these circumstances, but precisely how, we're not sure."
<p>
I finished off with a quote by Arthur C. Clarke who wrote in 1973: "Any sufficiently advanced technology is indistinguishable from magic." -- by that definition, Amateur Radio and the "FM capture effect" is clearly magic.
<p>
For me Amateur Radio is about the constant quest of learning, the ongoing pursuit of explanation and understanding, the relentless curiosity that burns a hole in my mind waiting to get filled with information and knowledge about anything and everything.
<p>
In that same environment I am the holder of the beginner's license in Amateur Radio and that is the cause for some members of our community to scoff at my skills, to demand that I upgrade, to ridicule the level of licence that I hold and to brandish their higher level certificate of proficiency as a weapon against my meagre understanding of this hobby.
<p>
How is it possible that this irrational belief that one license is more valid than another can exist in a world where something as basic as the "FM capture effect" is not understood, not documented, not explained and not taught to those holding the summit of knowledge, the highest level of Amateur License?
<p>
I've been a student all my life and truth be told, that's true for most people I meet. There are a few people who know everything already, but the rest of us are able to understand that learning is a continual process. The level of license you hold has nothing to do with your ability to learn, your ability to understand or your ability to be a higher class of human.
<p>
A high level license is a privilege to incur a higher level of responsibility and acknowledgement that at some level you're able to walk and chew gum at the same time. Clearly for some it's the ultimate expression of their superiority, but for the rest of us it's a token that affords us extra access to radio spectrum and technologies.
<p>
One reason I'm raising this is because if you're a new entrant to our hobby, you might be confronted by Amateurs who demand that you update your license at their insistence, rather than your interest, which can lead to you leaving our community which is a regrettable and undesirable outcome.
<p>
Another reason I'm raising this is because there are many things in Amateur Radio like the "FM capture effect", phenomenon we know happen, but have little understanding about. These things have implications far beyond our hobby. For example, the mobile phone in your pocket, or the laptop on your knees or the wireless headphones on your head, all use technologies that are subject to the "FM capture effect" and understanding and research in our hobby can and will help the wider community.
<p>
So, don't let your lowly license deter you from learning, from participating, from being curious and researching things that interest you. Who knows, one day you'll add to the body of knowledge that we call Amateur Radio and we'll all be better off.
<p>
I'm Onno VK6FLAB
Listen:
Using an Alex-Loop, very satisfying ...
Foundations of Amateur Radio
<p>
The quest for the perfect antenna is likely to be one of the things that you'll carry with you during your entire Amateur life. In the past I've explained how the perfect antenna cannot exist and that the amount of variation inside just one antenna is infinite, so there is lots to choose from.
<p>
One of my friends loaned me an antenna called an Alex-Loop. It's a so-called Magnetic-Loop Antenna and while the physics of the antenna is fascinating, I'm not going to go into it today. Suffice to say that there are hundreds of articles on the subject on-line and if you do dive in, read at least 20 or so before you decide that you understand how it works or how to build one.
<p>
Until I used the Alex-Loop, I'd been using antennas that are set-up for a single band, or ones that require switching between bands, or using long-wire antennas with an SGC antenna matching unit. I've also used so-called antenna tuners, a topic worthy of discussion some other time.
<p>
When you use your radio to pick a frequency, so too do you pick an antenna setting with a magnetic loop. In this case, the user-interface is a knob that changes a variable capacitor to make the antenna match between 7 MHz and 30 MHz. As I said, I'm not going into the physics of this, but the outcome of turning the knob is that at one point for each frequency, the sound coming from the radio will peak.
<p>
As you turn the knob on the radio, you also turn the knob on the antenna. The two go hand-in-hand and the experience is a pretty satisfying one. No need to switch bands, get out of your operating position, change the band on your antenna, or switch a coax switch to another antenna, or transmit to make the antenna matching unit do it's thing, or to peak the antenna tuner, nothing like that, just a simple turn of the dial will get you to where you need to go.
<p>
The reason I'm discussing this is because it's the first antenna I've used, and I have played with hundreds of them, that is able to match the user experience of turning the dial on your radio with turning the dial on your antenna.
<p>
So far, operating from my QTH, where the noise is an abysmal S9, I managed one contact, which I have to tell you was great. It wasn't earth shattering, not even that far or noteworthy, but as contacts go, it was very satisfying.
<p>
Hopefully in the not too distant future I'll be able to find some time and go to a more RF quiet location and have some more fun.
<p>
I'm Onno VK6FLAB
Listen:
Getting an elusive contact ... fly-fishing style.
Foundations of Amateur Radio
<p>
There's a phrase that I use quite often, "Get on air and make some noise!"
<p>
In terms of Amateur Radio that makes people think that I mean that they should turn on their radio, pick a band and call CQ, for hours. I can tell you now, if you're a QRP station, this is going to be a frustrating experience unless you're lucky or happen to be located in a place where other Amateurs want to talk to you, like an uninhabited island, or a low-tide reef, or some other place on the DXCC most wanted list.
<p>
I liken operating a low power or QRP station to fly-fishing. To get a fish takes patience, skill and persistence. Would you start fishing in an industrial sewer in the hope that you catch something, or would you attempt to learn something about the fish that you're trying to catch, before seeking out its hiding place and throwing out a bait?
<p>
Operating your Amateur Station should be more of the baiting and less of the industrial sewer.
<p>
So what does this look like in your day-to-day operation of your station?
<p>
Well, for starters you'll need to figure out where all the other Amateurs are. You can do that by listening for other stations, or by finding automatic beacons and seeing if you can hear them. That takes care of the first problem, is it at all possible to catch anything here?
<p>
The next challenge you're faced with is when to find these stations. You'll need to do some reverse investigation. If you're trying to contact the other side of the globe, it's likely that the station you're looking for is going to be asleep when you're awake. So, calling a station during your lunch break is likely to mean that it's midnight over there. So, pick a time when they're likely to be awake, the beginning or the end of their day, which happily coincides with the grey-line, when the sun is just on the horizon, when radio propagation goes through some magical transformations.
<p>
If you call on a Wednesday, it's likely that they're also in the middle of their work week, so think about how to plan for this. If it's a public holiday, check to see if they have one too, or plan for operating during the public holiday at the other end. If there is a large Amateur Radio contest at the other end, you might find that your station is desirable as a contact, or the opposite might be true, so check that out.
<p>
Of course, I'm not able to cover all the variations of this and it will be specific to your station, so spend some time planning and learning about what a contact might look like.
<p>
Now, if you take this advice to the extreme, you'll end up never getting on air and calling CQ, which means that you'll never get a serendipitous contact, nor will you capture the exception where an insomniac operator is trolling the bands to talk to someone, which would be a shame, so, do your homework, learn about when and where to operate and in the mean-time, get on air and make some noise!
<p>
I'm Onno VK6FLAB
Listen:
What if the Radio Spectrum was a data souce?
Foundations of Amateur Radio
<p>
The evolution of Amateur Radio is a constantly changing landscape. I've previously described the transition from spark-gap to surface-mount and the ongoing progression of inventiveness that brings this amazing hobby together with the leading edge of science and technology.
<p>
If you think of software defined radio as a linear increment on the radio scale you'll end up where we see some of the manufacturers today are placing their bets. You'll find a radio that has knobs and buttons like a traditional radio, but behind the scenes there is a computer and a new way of accessing the radio spectrum.
<p>
A little further along the scale is the proverbial black-box, often with a single button to power it on, a few connectors for antennas and a network connection to get information to a computer. The software on the computer often attempts to resemble a traditional radio with similar controls and the combination of the box and the computer with the software running makes for an Amateur station.
<p>
If you have no rules for how the user must interact with the radio, you might come up with interactive waterfall charts that display the radio spectrum as a graph, showing frequency along the horizontal axis, time across the vertical axis and colour as a measure of signal strength.
<p>
Each of these experiences are attempting to achieve the same purpose, making the radio spectrum available to the station operator.
<p>
If you completely decouple the concept of radio from this and look at the spectrum as a source of data, then processing that data, often in real-time, becomes less constrained by the limits of our current perceptions of how a radio works and moves into the realm of data science.
<p>
To give you a concrete example, if you've scanned a photo on your computer and are confronted by little dots of dust, there is software available to remove that dust and re-create the image in much the same way as the original might have been. The process is called noise reduction. That same process could also be used to process radio spectrum, or audio.
<p>
There are many concepts that exist outside radio that can be used in this new world. You could do live analysis of the bands, determine which signal had the best chance of getting to the intended recipient, you could decode information spread across multiple bands, with bandwidth use that could be measured in gigahertz, rather than kilohertz.
<p>
With the limits of your mind as the only barrier, what other inventions might be arriving at our doorsteps in the near future?
<p>
I'm Onno VK6FLAB
Listen:
The evolution of our hobby is now ...
Foundations of Amateur Radio
<p>
The hobby that we call Amateur Radio has been around for over a century. During that time we've seen it evolve from capacitors, inductors, through valves, then diodes and transistors, through to integrated circuits, chips and surface mount components. Along the way we collected a vast body of knowledge and experience which combine to make the hobby what it is today.
<p>
You might have noticed that the progression of our hobby didn't stop with surface mount components, it's still evolving through software and the next frontiers are already tentatively being explored and offered for sale to curious amateurs.
<p>
In my day job I'm a software engineer and I adopted Amateur Radio as my hobby of choice because it was technically diverse, had a rich history, a large community and had little to do with my day to day pursuits in computing and information technology. How wrong was I?
<p>
This morning I started writing code to visualise audio, specifically in my case to make a video version of this weekly segment, but also to experiment with how we as humans use our senses to decipher information. As I was buried inside the decoding of audio it occurred to me that what I was doing was the equivalent of soldering together a circuit for the purposes of learning more about some aspect of my hobby.
<p>
This in turn made me realise that as we dive deeper and deeper into the software defined radio universe, more and more of what we as individuals can do will be based on computers, algorithms and maths.
<p>
On the face of it, this is an enormous shift in perspective, but I'd hazard that it's no different from moving between a spark-gap transmitter and an AM transmitter, or moving from AM to SSB, or the introduction of transistors. Each of those changes now look pretty small with hind-sight, but at the time that they occurred their impact must have been immense.
<p>
I made contact with the software defined radio community a few weeks ago and in between my work I'm slowly beginning to explore this new universe that is beginning to unfold.
<p>
Of course, as this evolution happens, while we're in the middle of the transition, as-in right now, there'll be discussion about the difference between digital and analogue, between hardware and software, about the benefits and pitfalls, no-doubt mirroring prior discussions that have been had across the past generations of amateurs.
<p>
A new dawn has come and the future is here, come and join the fun.
<p>
I'm Onno VK6FLAB
Listen:
Things you can learn from a new operating environment ...
Foundations of Amateur Radio
<p>
The other day I had the fortune of using a club station with an Advanced License whilst mobile using more than my usual 5 Watts. I was driving in convoy away from the main local 2m repeater and was interested in finding out what the coverage might look like and how high power might make a difference. When I say high power, that's 50 Watts FM on 2m.
<p>
I learnt several things during my journey.
<p>
First of all, line of sight is still true, even with more power, but there is more margin for error. Little obstacles that would cause a 5 Watt signal to be absorbed before it got to the other end are all but invisible with full power. Don't get me wrong, a hill is a hill and a radio signal won't go through it, but trees, houses, and all the other little things we humans build on the planet each obstruct a little bit of signal. Higher power gives you more margin and less effect on the resulting audio.
<p>
The next thing I learned is that two cars, travelling in convoy can overwhelm each other with power. The way you experience this, is that the other car starts talking, and all you hear is mush. As they drive away from you, at say a traffic light, their signal becomes clearer, to the point where it's back to normal. The way it sounds is almost as if the signal to noise ratio is being adjusted, more signal, less noise as the distance increases - a very strange sound to hear.
<p>
As it was explained to me, the phenomenon relates to the receiver being overwhelmed by the very strong signal nearby. I'm guessing that the AGC, Automatic Gain Control is reducing the sensitivity of the receiver, to compensate for the strong transmission nearby, which in turn means that it is unable to hear the repeater which is relaying the same signal on the receive frequency. As the distance from the strong transmission increases, the AGC compensates, increasing the gain, thus making the receiver able to hear the repeater.
<p>
There wasn't the opportunity to experiment too much, being in a moving vehicle, but I wonder if changing the AGC setting would have made a difference. I suspect that there is more going on than just the AGC, since the signal from the nearby transmitter, the one in the other car, is still exciting the receiver, even if the gain is being adjusted. I suspect, but don't know for sure, that theoretically, I would have been able to hear both signals, the outgoing one from the other car, even though it's 5 MHz off frequency and the incoming signal from the repeater. Likely there was a minuscule delay between the two, perhaps even to the point of suppressing each-other.
<p>
Another question that comes to mind is a phenomenon called the "FM Capture Effect" as well as the so-called "near-far problem" and I'm wondering if this is another aspect of what I was hearing and if we had a local AM repeater, would it exhibit the same behaviour?
<p>
Now, as you might have guessed, there is very little in the way of research in my comments here, but that wasn't the point of what I'm talking about. The point was that a slightly new operating environment introduced me to concepts I'd never considered, never even really knew about, other than in a theoretical sense and I was able to actually see, well, hear, this in real life.
<p>
Given my track record with over 300 different episodes, you can take for granted that I'll be digging deeper into the experience to see what I can learn and to see if my initial observations bear any relationship to reality, or if I'm adding two and two together and coming up with five.
<p>
I'm Onno VK6FLAB
Listen:
What to say on-air?
Foundations of Amateur Radio
<p>
There's a confession I'd like to share with you. Chatting on air is something I rarely do.
<p>
When I'm working distant stations, so-called DX, my typical exchange is: AB0XYZ, you're 5 and 9. If the station has some questions to ask, I'll answer, but often times there is no conversation and I'll move on to the next one.
<p>
Some of that can be explained by my initial training as an Amateur. I started working lots of stations in a contesting environment. I took to it as a duck to water and never looked back. No doubt I have lots to learn and I cannot guarantee that my callsign recollection is as good as I think it is, not to mention being able to detect an incorrect callsign, since I still have little knowledge in which callsign prefix, the first part, belongs to which country.
<p>
Another explanation is that I'm often QRP and just very happy to be able to make the contact in the first place.
<p>
I hear stations on-air having a great chat, a so-called rag-chew, but I never seem to find something interesting to say or relevant story to share with a stranger. Sure I can talk. As you might have gathered from listening to me here, I'm never short of something to say, or an opinion to venture, but being sociable is not one of my stronger traits, never has been.
<p>
A few of our local Amateurs have a tendency to tell stories that go on for so-long that they time-out the local repeater, to the point where one repeater has been set to a 15 minute time-out just to cater for verbose exchanges. I immensely enjoy the stories, but often find myself wondering what I might contribute without sounding like I have tickets on myself.
<p>
I recently was asked by a new Amateur what to talk about. Their daily commute is a 30 minute car ride to and from work and chatting on the repeater seems like a logical thing to do, but they asked me what to talk about. Stuffed if I know.
<p>
Seriously though. The very first part of chatting is to actually turn on your radio. The next part is telling others that you're there. Then when they do, ask what they've been up to and before long there is a conversation under way.
<p>
The funny thing about all this is that while I'm pretty quiet when it comes to being on the local repeater, I do host a weekly 'net for new and returning Amateurs and when asked I'm more than capable of standing my ground and venturing my opinion.
<p>
Perhaps I just need to practice more and perhaps if you find yourself at a loose end on a topic of conversation, feel free to make fun of me or to raise a topic that's something I've talked about. Who knows, we might both learn something.
<p>
I'm Onno VK6FLAB
Listen:
Amateur Radio Community Standards
Foundations of Amateur Radio
<p>
The Amateurs Code, originally written in 1928 has been quoted for almost a century. A Radio Amateur is Considerate, Loyal, Progressive, Friendly, Balanced and Patriotic. There is something almost romantic about that, but in my short life as an Amateur I've been exposed to much that leaves that as just a sentiment, rather than a social code. I'm not alone in that. I have numerous emails from Amateurs around the planet who share their negative experiences, often being bullied by self-proclaimed experts with an axe to grind.
<p>
Our 1928 Amateur Code brings with it a sense of decorum, etiquette, but other than some true Gentlemen I've had the pleasure to meet, there are aspects about our community that just don't translate into today, even if the Amateur Code could lead the way.
<p>
Our community of Radio Amateurs represents an opportunity to engage with society, to attract new blood, to include new ideas and to lead the way in community engagement. As one path towards growth of our hobby we have started talking about STEM, Science, Technology, Engineering and Maths as one way to relate to a wider community. That's a great sentiment, but I think we need to do some housekeeping before we embark on that journey.
<p>
Amateur Radio is steeped in tradition. We use quaint terms such as OM, Old Man to describe each-other, YL, Young Lady to describe women in general and XYL for wives of Amateurs. We have a thing called a "Gentleman's Agreement" and we generally refer to Amateurs as He and Him.
<p>
By doing that we've essentially limited our audience to 50% of the global population. We alienate women before we even start to engage them and when we do have female participation we get Facebook posts full of sexual innuendo, or outright sexist comments, not to mention the girlie pictures spread around the globe, sniggeringly exchanged as contact QSL cards. On air we alienate women, make disparaging or sexual comments or express our amazement that a mere female could achieve a license.
<p>
What are we, pubescent boys? Is that the best we can do? The irony is that we as a community rarely discuss politics or religion. It's just not the done thing.
<p>
In general day-to-day exchanges we use inclusive language. In our workplace we are sensitive to people who are different and in our laws and rules we champion equal rights for all humans, be they men, women, gay, straight, yellow, black, purple or intersex.
<p>
Why is our Amateur language not inclusive in a hobby that is based around communication, where Amateurs clamour to work a pile-up on a rare DX station in some war-torn part of the globe, where science and rational thought are expected and where an Amateur Code written in 1928 encourages us to be Considerate, Loyal, Progressive, Friendly, Balanced and Patriotic?
<p>
I think we need to take a long hard look at ourselves before we start going into schools and sharing what our amazing hobby is about.
<p>
I'm Onno VK6FLAB
Listen:
Beauty is in the eye of the Beholder
Foundations of Amateur Radio
<p>
There is something magical about getting a new radio. I remember it well. Fondly even. I had done the research, consulted my bank account and picked my radio. It arrived in a courier delivery and I sat at the kitchen table, opening the box and marvelling at the parts that made up my first purchase as a radio amateur.
<p>
I'd joined my local radio club a month earlier and proud as punch I took my shiny new box of joy to the club and showed it off to anyone who came near. I vividly remember one member's first comment: "Wow, that's an ugly radio!"
<p>
I was heart broken, insulted, confused and didn't quite know what to do with that experience. My radio was beautiful, tiny, special. It was just what I wanted, it wasn't ugly and besides, it was mine. As irony would have it, several months later I saw their radio and thought that it wasn't something that I would like to bring home.
<p>
Fast forward six years.
<p>
The other week, I went to a local Ham-fest, it's a place, often a local hall with tables around the edges stacked full of an amazing array of stuff, where amateurs come together to meet and exchange their obsolete junk, uh, surplus equipment. It's not uncommon to arrive at a Ham-fest with one box and to leave with two.
<p>
Among the tables and amateurs I was introduced to a new radio. I looked at it and in my head I thought: "Wow, that's an ugly radio!" - fortunately I managed to keep the thought to myself and instead asked the amateur who was showing it off about how it worked, how they liked it and what it cost. The amateur was excited to share their thoughts and I learned something from the exchange.
<p>
When I got home I searched the 'net for some more information and found that this particular radio was more than it appeared and that my initial dislike of the visual translated into an interest that might yet see me as the owner of that radio.
<p>
I know you're busting to ask which radio and which amateur, but I'm not here to advertise any particular radio, just to observe that beauty is in the eye of the beholder and that things can change once you know more.
<p>
I wish I had those words to share with the first person who told me that I had an ugly radio, but I'm pleased that I have them now.
<p>
So, beware, ugliness is an emotion, not always accurate and if you experience it, bite your tongue and learn something first.
<p>
I'm Onno VK6FLAB
Listen:
An Amateur Radio Code of Conduct
Foundations of Amateur Radio
<p>
The Hobby of Amateur Radio is a curious mix of technology, rules and people. If you're new to this you're likely to find yourself being swept up in the scale of the experience and more than I think is appropriate you'll find yourself at the pointy end of a barb by another member of the community.
<p>
It's taken me over six years to begin to understand what is going on that is causing this. Let me start by saying that there is no place for bullies in this society. Correcting a mistake is one thing, but causing interference, transmitting insults, abusing people on air, ignoring new-comers or using social media to vent is just not appropriate.
<p>
Bullying aside, after looking at posts on social media for a while, it occurred to me that much of what lies at the root of this behaviour is a fundamental mismatch between how licensing is achieved today, compared to how it was achieved historically. I see regular references to the type of examination. For example, historically examinations were conducted using full written exams, where today we are likely to use multiple-choice methods and even those are being reviewed.
<p>
It occurs to me that historically, the process of becoming a licensed radio amateur was a slow and steady process, infused with deep contact with an existing amateur, regular training, exposure to the community, on-the-job training, interspersed with study and then finally an examination.
<p>
Today, the process is more likely to be a much quicker affair, with initial exposure to the hobby, a visit to the local training facility, either face-to-face, or on-line, followed by an examination.
<p>
If we assume for a moment that both examinations are the same in terms of assessment, and I know that in and of itself is controversial, what else is different between these two processes?
<p>
The answer is the deep contact while learning. In the United States this is referred to as Elmering, in Australia it's called Mentoring and it isn't the same as it used to be. Today there is mentoring going on, lots of it, but often that's after someone has actually received their credentials as a licensed operator.
<p>
We assume that the examination prepares us for the hobby, but actually, the examination just prepares you for the law. That is, holding a certificate of proficiency means essentially that you are now legally aware that you can create interference and that you are liable if you do so.
<p>
As I said, the deep contact during the learning process is different. That deep contact exposes a new amateur to the unwritten rules and customs that form part of the community of radio amateurs across the globe. For example, we use Lower Side Band or LSB below 10 MHz and Upper Side Band or USB above 10 MHz. There is no technical reason, just historical ones, that make that this must be so.
<p>
There are many, many such un-written rules about amateur radio. Often they are referred to as the "Gentleman's Agreement" - and I'll leave aside for a moment the gender issues related to that notion. This so-called "Gentleman's Agreement", is not written down, it's passed on from amateur to amateur, or assumed to have been magically acquired by the process of osmosis.
<p>
So, a newly minted Amateur, truth be told, I'm one of those, steps into the stream and gets swamped by rules that appear from no-where and instead of getting chapter and verse on how to learn, the amateur gets insulted and ostracised.
<p>
It is clear to me today - more than it has ever been - that old hams die hard. They are responsible for their legacy and if they want to maintain the hobby in their image, they're required to be inclusive and assist new amateurs, rather than insult them and drive them away.
<p>
I know that there are many wonderful amateurs in our community who do just that. However, the noisy ones just want the new amateurs to get off their lawn and go and play with something else, preferably not in their patch.
<p>
I have no doubt that I'll get flurries of people who feel insulted by what I have observed and to those I can only say: "If the shoe fits..."
<p>
For the rest of us, it's time to get on air and make some noise. Document any rules you come across and perhaps one day we'll have a code of conduct that radio amateurs can hold up to the world as an example of tolerance, inclusiveness and encouragement. If we're lucky we can even incorporate the Amateurs Code, originally written in 1928. A Radio Amateur is Considerate, Loyal, Progressive, Friendly, Balanced and Patriotic.
<p>
We can dream.
<p>
I'm Onno VK6FLAB
Listen:
What is SOTA?
Foundations of Amateur Radio
<p>
One question I get asked regularly is: "What's the point of Amateur Radio?" Today I'm going to begin to answer this perennial question. As you know, this activity is a hobby, something you do for your personal enjoyment. People get pleasure from a vast range of undertakings and if you combine multiple such adventures into your life all the better.
<p>
Amateur Radio is a hobby in and of itself, but it's also an enabling hobby. What I mean by that is it often can act as an excuse to do something else - under the guise of being Amateur Radio. For example, you can use an activity called SOTA to add some fun into your life.
<p>
I've spoken in the past about SOTA, Summits On The Air. It's a way to enjoy being outdoors and climbing across the globe, as well as an excuse to participate from the comfort of your shack to encourage climbers and even as an unlicensed radio enthusiast, you can also participate.
<p>
SOTA started in 2002 with the publication of the General Rules which outline all that the community expects and needs from you if you participate. In the intervening years the document has grown to 23 pages and I confess I was not looking forward to reading it all and truth be told, I've not yet digested the finer points, but I will before I next climb up a mountain.
<p>
Don't get me wrong, it's not an onerous document, it's laid out well, describes precisely what's involved, how it's structured, who to ask questions of, what code of conduct is expected and what constitutes a valid SOTA activity.
<p>
As I said, before I next climb up a mountain - more precisely, in SOTA terms - it's a prominence, something sticking out of the earth. Before you start gathering maps and looking at tall rocks, a prominence isn't just about how tall it is, but also how close other peaks, there's a whole definition of this idea, but the SOTA volunteers have done all the work, so you don't need to get technical to get on-air.
<p>
There's rules about getting to a peak, about being there, about the environment, about how to use callsigns and the use of cars and other things, so before you get yourself into strife, like I did, read the rules.
<p>
There's three kinds of participants, an Activator, someone who climbs up the mountain, gets wet, gets snowed in, gets hot and sticky, eaten by mosquitoes, breaks stuff and does all the hard work. The second type of participant is the person in the shack behind their radio, on the listen-out for new activations, making contacts, logging them and gathering points. The final group of participants is the Short Wave Listener or SWL, who logs contacts, showing both sides of the communication, both stations heard, etc. An awards system exists for all three participants.
<p>
SOTA is a global activity. On the face of things it might seem daunting and my highlights of the notion that there are rules should not deter you from actually participating. The rules are to ensure that people don't get into trouble and die, to make sure that everyone has a good time and to deal with disputes as and when they arise.
<p>
Many resources about Summits On The Air can be found online, but your starting point should be http://sota.org.uk where you'll find a welcoming and active community of enthusiasts who also like being on-air and making noise from weird and wonderful locations on top of big rocks.
<p>
The point of Amateur Radio is to find something that you enjoy doing and making it a shared experience by incorporating your radio. A bit like Mark Twain said: "Golf is a good walk spoiled", SOTA is a mountain climb enhanced.
<p>
I'm Onno VK6FLAB
Listen:
Adding a stroke to your callsign ...
Foundations of Amateur Radio
<p>
To sign or not to sign, that is the question. Last week I spoke about operating with low power, or QRP which sparked a lively discussion which evolved into a conversation about adding bits to your callsign to indicate some extra information.
<p>
For example, some stations will add stroke QRP to their callsign when they're operating low power when others don't. Other examples are adding stroke Portable or stroke Mobile.
<p>
Let me start by saying that I'm not familiar with the rules in countries outside Australia, but I'd be surprised if they're much different, since callsigns follow a global standard, but check your local laws before you start getting on-air to make noise.
<p>
In Australia the rules, the Radiocommunications Licence Conditions (Amateur Licence) Determination 2015, commonly referred to as the LCD has nothing to say about any such addition to a call sign. There is no mention of low power operation, mobile operation, marine operation or any such thing. The reference to portable operation discusses how long you're allowed to operate a portable station without notifying the regulator.
<p>
So, from a legal perspective, there is no such thing as a stroke anything.
<p>
So where does this addition of stroke QRP, or stroke Mobile or any other variation come from?
<p>
The regulator maintains a website that has a page called "Amateur operating procedures" which "can help prospective amateur operators". It details types of transmissions, discusses code words like QRP and has one set of comments about adding something to a transmission when operating mobile or portable.
<p>
It suggests that you can say something like: This is VK6FLAB operating portable on Wave Rock, and if you're operating outside your state, suggests that you might shorten that to VK6FLAB/5 when operating in South Australia or VK5.
<p>
So, there is no such thing as stroke Portable, stroke Mobile, stroke QRP and the only suggestion from the regulator is that you indicate that you're mobile or portable and help by indicating your state if you're not operating within your home state.
<p>
In the past few years I have signed with VK6FLAB/QRP but after realising that this causes much confusion in logging, I have stopped doing it. These days you might hear me say that I'm operating QRP during a CQ call, to help other stations a little, but I've often found that it's really not worth the extra breath.
<p>
I'm Onno VK6FLAB
Listen:
Life's too short for QRP...
Foundations of Amateur Radio
<p>
A phrase I hear regularly is "life's too short for QRP" and today I think that it's appropriate to start a conversation about that sentiment. When propagation is poor the high-power amplifiers get on air and use it to prove that you need power to get out and about.
<p>
Far be it for me to deny another amateur the pleasure of working a thousand stations at the same time, a so-called pile-up. It's a thrill. I've done it during contests. It's fun. You call CQ and the biggest problem you're faced with is deciding on which station to pick.
<p>
In the past I've mentioned that I've made a contact with Cuba, about 18,000 km away using 5 Watts. Over the weekend I managed just under a third of the distance, Perth to Tuvalu, 7,000 km with a wire and 5 Watts. You could take away from this that I like bragging about my contacts and it's true that I'm proud of having achieved those things, but that's not actually what I want to talk about.
<p>
Amateur Radio is a lot like fishing. You can go out and throw a stick of dynamite into a pond and pull out all the fish, or you can stand up to your armpits with a reel in your hand casting a fly to catch a fish. Operating QRP is like fly-fishing. It takes practice, patience and perseverance. Of course it's not for everybody, but then neither is fly-fishing.
<p>
If you hold an introductory Amateur Radio license like I do, the rules of engagement restrict how much power you're allowed to use. For some this restriction appears to inhibit their ability to enjoy the hobby. This podcast started life some six years ago precisely because a new entrant was expressing their need for more power.
<p>
My contact over the weekend wasn't particularly earth shattering. It was made with a minimum of equipment, a wire antenna on a squid-pole strapped to a house, simple radio, running off a battery in preparation for a contest that was happening the next day. The thing to note is that it happened on 40m, using 5 Watts and the distance was twice the maximum distance within my own country.
<p>
This means that any amateur who is starting out can achieve the same thing. It means that you might need to review your assumptions if you think of a 4,000km distance between stations as a hurdle that cannot be overcome.
<p>
The take-away should be that while QRP is not for everyone, it's a perfectly valid way of enjoying the hobby and smelling the roses along the way.
<p>
In case you're wondering, yes, I was wearing a grin from ear to ear after making my contact. Better still, I didn't have to kiss any fish.
<p>
I'm Onno VK6FLAB
Listen:
What is a resistor?
Foundations of Amateur Radio
<p>
Last week I was casually asked "What is a resistor?" Now if you're into electronics like many radio amateurs, you'll instantly have a picture of a little blob with two wires with pretty colours painted on the outside, the size of a grain of rice and if you're not into electronics, you now know what a resistor looks like.
<p>
Before I talk more about resistors, I'm going to talk about a stick.
<p>
If you pick up a stick and poke something with it, some interesting stuff is actually happening. You move your hand at one end and the other end moves at the same time. Obvious right? It's a stick. On a molecular level something else is happening. The atoms under your hand inside the stick move back and forth with your hand as you move it. The atoms next to those atoms do the same thing. The atoms next to that, all the way to the end, also do the same.
<p>
Now you likely have a picture in your mind of a solid stick. On a molecular level, this isn't solid at all. Instead of a solid stick, imagine having a row of ice-cubes with a little space in between each one being bumped by the previous ice-cube. The ice-cube closest to you moves with your hand, the one next to that gets bumped, all the way to the end.
<p>
With ice-cubes there is a noticeable delay if the gaps are visible, but the delay gets smaller and smaller if the cubes are closer and closer together.
<p>
In an electrical wire a similar thing is happening. You might have a picture in your mind of electrons travelling from one end of a battery, through a wire to the other end of a battery. Except that's not what is happening. While electrons do move, very slowly, it's called the drift velocity, think centimetres, or inches per hour, turning on a light is instant.
<p>
It's instant because each atom affects the one next to it, which does the same to the one next to that and so-on. While not exact, this happens roughly at the speed of light. This is beginning to look a lot like a stick. Push at one end, something happens at the other end, almost immediately.
<p>
Instead of ice-cubes, but in much the same way, we're actually moving an electrical charge from one end of a wire to the other.
<p>
It takes energy to keep a charge moving along a wire. The amount of energy used is the resistance of that wire. Not all materials act in the same way. Some, like silver or copper, use little energy or have low resistance, while others like carbon, use more energy and have high resistance.
<p>
You'll find resistors made in many different ways of various different materials. Each one is made for the specific purpose of using a defined amount of energy to pass along a charge.
<p>
There are resistors made of carbon and of thin film of conductive material sometimes with laser cut paths to make them appear as a long maze of conductive material and of very thin wire, tightly wound together. This kind of wire resistor has a side-effect in that a tightly wound coil like that has some properties that we use in Amateur Radio, we often think of these kinds of devices as inductors.
<p>
But that's another story for another day. As a side note, I started using coulombs, joules, volts, amperes and ohms to explain this, but I figured that it wasn't needed to understand how it actually works. If you have some time, look into it, the maths is fascinating and pretty straight forward.
<p>
I'm Onno VK6FLAB
Listen:
Checking your On-Air signal...
Foundations of Amateur Radio
<p>
The other day I managed to achieve a little personal milestone. I heard myself on-air. Before you get all misty-eyed, yes, I've heard myself on-air before - probably on thousands of occasions over the years, but that's not what this was. This was my own transmitter, in my shack, transmitting my voice via SSB and it being received and me hearing it.
<p>
In broadcast radio this is a common thing. Every radio station I've ever been in pipes the audio from a normal radio receiver into the studio, so you can confirm that your transmission is in fact going to air as expected. There are funny stories associated with experts who decided that they didn't need to wear headphones and promptly broadcast silence because their microphone volume was turned down or not plugged in - gotta love the helpful announcer in the previous shift.
<p>
So, what was so special about hearing myself this time?
<p>
Well, for the first time I heard my SSB voice. Not AM, not FM, SSB. I'd tried this before using two radios and a dummy load, but that just ended up in distortion, not much fun.
<p>
Let me tell you how I managed this and what I learned along the way.
<p>
Online I found a local Software Defined Radio, or SDR, that had the ability to tune to a frequency that I am allowed to transmit on. That seems pretty straightforward, but in actual fact getting those three things, Online, Local and Frequency all together has proven to be a bit of a challenge.
<p>
I started listening to the station to see how their signal compared to mine. I have a project sitting on my shelf to put together my own SDR, but that ran into some procurement issues, so I've been limited in my ability to experiment.
<p>
I started out trying to listen to the local HF beacon, part of the Northern California DX Beacon network. Turns out that the SDR and I can hear that pretty equally.
<p>
I did notice that there was about a five second delay between what I heard off-air and what the SDR sent to me across the Internet. I don't know if the delay is because the Internet signal travelled back and forth across the country a couple of times, or because this particular SDR has some delays.
<p>
I tuned the SDR to 28.490 and my radio to 28.490 and after checking if the frequency was in-use started some test transmissions. Nothing was working. No noise, nada. It does help if you plug the right antenna into the radio. Tada, look Ma, it makes noise! I could hear myself.
<p>
It became clear that there was a difference in what I was expecting to hear and what I actually heard. Playing with different modes didn't seem to make any real difference, so I was a little stumped.
<p>
I recalled that during a contest I had been advised that I was off frequency, so I played with my Tuning Dial, known as the VFO, and adjusted my frequency to 28.489.50 and there I was, just like I expected. Five second delay and all.
<p>
At that point I wondered if this meant that the SDR frequency was wrong, or mine, or both - how could I prove it? Some hunting around for suggestions revealed the idea of tuning the SDR to one of the time frequencies, on 5, 10, 15, 20 and 25 MHz, better known as WWV and WWH. On these frequencies a 24 hour a day transmission happens that encodes the time. You'll hear a ticking clock, voice indicating time and it has all manner of extra information encoded in the signal. It's used as a time standard but also as a frequency reference. Best results are when you use AM and you can use it to get a sense of propagation between you and Colorado in the United States. Mind you they are using a few extra Watts.
<p>
Zooming right in I could see that the SDR was indicating that it was bang on frequency, so I'm about 50 Hz off, high as it happens. Which just means that I need to tune a little lower than the frequency I want to be on and I'm good to go.
<p>
Only I'm not yet convinced.
<p>
I came across settings on my radio, the TX Carrier Point for USB, menu 18 on my Yaesu FT-857d. Other than various wild guesses by others, I still don't know what it actually does, all I do know is that it was set to 150 Hz. Setting it back to 0 didn't make the problem go away, but it did appear to improve things.
<p>
Not sure yet if my radio is in need of a doctor, or if I am in need of some instruction, either way I'm sure you or a friend knows and is willing to share.
<p>
Turns out, I sound just as sexy on SSB as I do on FM. At least my wife thinks so.
<p>
I'm Onno VK6FLAB.
Listen:
If they're shooting at you - you know you're doing something right!
Foundations of Amateur Radio
<p>
There's a quote from a television show that speaks greatly to me. "If they're shooting at you - you know you're doing something right!"
<p>
I've been producing this weekly recording since May of 2011. It started life as "What use is an F-call?" and the first episode was recorded in response to an Amateur who bemoaned their transmitter power restrictions associated with their beginners license - when I used the same power to speak to a station 15,000km away the week before. I named the segment after the common term for my license - a Foundation License - in Australia known as an F-call. It's the so-called beginner's license, something you can get by spending a weekend with a book and passing a test that introduces you to the hobby of Amateur Radio.
<p>
Since that first recording I've produced 296 different episodes, it was renamed to "Foundations of Amateur Radio" and I started putting the recording online as a podcast. In those episodes I've covered many different topics, from what to spend your money on, how to get started, what antenna's do and how you can build them, how different technologies work and what the Amateur Radio community is like.
<p>
A recurring theme in my recordings is the attitude of other Amateurs to those who are starting in the hobby. I come back to it regularly because I keep getting emails from listeners who are subjected to varying levels of abuse by other Amateurs. I've taken to going to the Amateur Training College to explain that Amateurs are a mixed lot, many wonderful people and some rotten apples who make a lot of noise.
<p>
I have had messages detailing abhorrent behaviour and read messages of those who left the hobby because of it.
<p>
Fortunately the opposite is also true. I have messages from people who came back to this amazing adventure and got inspired by some of the things I've said and used this to rekindle their interest, or to finally go for their license, or to finally pluck up the courage and press the Push To Talk button on their radio and speak.
<p>
We all make mistakes. I know I do. Sometimes I even find out that I made a mistake. For example, last week an Amateur told me that I'd claimed to have had 45 years of Computing Experience, which would make me a toddler when I started. Turns out he's right, I did claim that. Whoops. I meant to say 35 years, but wait for a bit and 45 years will be close enough. It's a shame that he didn't comment on the actual content of the segment, namely that we have a pre-conceived idea of what constitutes an Amateur, even though that is a changing thing. The episode is called "We should stop requiring electronics to be amateurs.", episode 28 of Foundations of Amateur Radio if you're interested.
<p>
It's also a shame that he didn't point out a much larger error, in my episodes about chickens, but another Amateur, who sat on this for some time because he wasn't sure, caught up with me for lunch and we discussed in great detail what our common understanding was. We're still working out how exactly I explain what I said and how it differs from reality, suffice to say, I'm a curious kind-of-guy and I like to learn.
<p>
That learning is also a regular topic of attack. It seems that some Amateurs who in the words of a wise-man - "who's only achievement in life was to pass their Amateur License" use my continued status as holder of a Foundation License as evidence that I'm clearly not able to pass my exam and ridicule my excuse of a License to claim that I want to talk to the world using 5 Watts before changing license.
<p>
I've said it before and I'll say it again. This is your hobby. If you gain pleasure from getting a higher level of responsibility, then by all means do so. If you need something that your current license doesn't have, go for it. For me, my license does exactly what I want today, nothing more, nothing less. I have enough privileges to achieve what I want from this hobby today and my lowly license did not prevent me from spending every week learning something new about this hobby.
<p>
As this recording gains in popularity I'm expecting more and more people to take pot-shots at me. As I started, "If they're shooting at you - you know you're doing something right!" - taking pot-shots as keyboard warriors is pretty easy to do. Seems that it's much harder to actually engage in a meaningful conversation about the topic at hand.
<p>
You might be listening to this and wondering why I'm bringing this up. Simple really. You are an Amateur, you're likely to be interacting with other Amateurs. Some of those will be helpful and friendly and others will be the opposite. I'm talking about this to make sure that you don't loose track of why you became an Amateur and to keep enjoying this wonderful hobby.
<p>
I love this hobby. It challenges me every week and it gives me a thrill every time I learn something new. I hope that I'm not alone in that.
<p>
I'm Onno VK6FLAB
Listen:
The spirit of our hobby ...
Foundations of Amateur Radio
<p>
Over the past six years or so I've single mindedly been producing a weekly segment about Amateur Radio. Over time this has evolved into a podcast which gets about half a million hits a year. Naturally I receive emails and I do my best to respond in a timely fashion.
<p>
One of the other things I do is announce a new edition of the podcast on several different sites where listeners have the opportunity to share their views about what ever is on their mind. Sometimes their response is even about the podcast itself, though I confess that some comments appear to indicate that listening isn't part of a requirement to actually form an opinion about what it is that I have said that week.
<p>
All that aside, I find it immensely fascinating that the responses I receive vary so much in perspective. It's not hard to understand and observe that our community comes from people along all walks of life. From nine-year olds to ninety-year olds and everything in between.
<p>
I tend not to comment directly on such feedback, since everyone has their own opinion, but I came across one post recently that made me sad about the spirit of some Amateurs. In a seemingly bygone era there was a sense that Amateurs would help new people join the community and help them find their way into this vast range of discovery. A place where no question was wrong, where shared experiences are cherished and where the lack of knowledge was an opportunity for learning.
<p>
It seems that the moniker that we carry, that of HAM, supposedly because when compared to Professional Telegraphers, we were considered HAM-fisted, went on to form the basis of a proud tradition of experimentation and renewal. Across the globe we see a refresh of the license conditions on a regular basis. We saw that here in Australia with the introduction of the so-called Z-call and K-call, looked down upon by Real Amateurs who had a much more stringent licensing regime.
<p>
We discontinued Morse Code as a requirement for an Amateur License as part of a global treaty agreement in 2003. In Australia this meant that from the 1st of January 2004, Morse Code was no longer required if you wanted to obtain an Amateur License. As you know, that didn't signal the end of Morse, just that it wasn't legally required any more. I'm one of many Amateurs learning Morse because I want to, not because I have to. I'd also point out that it was discontinued by global agreement, not two random guys in Canberra.
<p>
Back to my point about the spirit of this hobby. The point that was being made is that the Foundation Class license isn't a real license and that it is just being handed to anyone who asks, not like their requirements for Morse Code and a written exam, rather than a multiple-choice test. Essentially conveying that my undignified license and that of my fellow Foundation Licensees isn't to be confused with the noble one that a Real Amateur holds.
<p>
This kind of response saddens me and frankly I hear it too often. It's as-if we as a community still have not learned that the world moves on. Technology, in many ways the basis of Amateur Radio, evolves.
<p>
For example, in the current requirements for an Amateur License there is a long-winded discussion about the impacts of spurious transmissions on Analogue Television. In Australia, the last Analogue TV broadcast happened on the 4th of December 2013, that's years ago, but it's still required reading on the Amateur License Syllabus.
<p>
Similarly we learn about Valves, but attempting to actually obtain such a device is nigh-on impossible. Should we still be learning about those aspects of Electronics, or should we move on?
<p>
Amateurs are an inventive lot, we make up new modes, link up new technologies, experiment with all manner of stuff and sometimes we end up with something new, like IRLP, AllStar, SDR, Digital Modes and the like. All because someone got curious, couldn't help themselves and started to fiddle.
<p>
As things fall off the radar at one end, Analogue TV, Morse Code, Valves, the other end picks up things, JT65, Digital TV, Lithium Polymer Batteries and whatever else comes around the corner.
<p>
So, I'm sad that there are people who feel that my license isn't a real one. As many of my peers, I have a piece of paper from my regulator that begs to differ and a community of enthusiastic eager people who are attempting to find their home among our hobby as it evolves into the future.
<p>
Last week I talked about the death of our hobby and that it was vastly mis-represented. As I said, year-on-year, more and more Amateurs join, but overall the numbers decline. I think that opinions expressed about the lack of real licensing, decrying the death of Morse etc. is a symptom of why it is that we have a retention problem in our hobby.
<p>
Everyone is entitled to an opinion, but that doesn't mean I have to agree. This is my hobby too and disdain is my fuel!
<p>
I'm Onno VK6FLAB
Listen:
This hobby is dead ... NOT!
Foundations of Amateur Radio
<p>
Recently I was told that Amateur Radio as a hobby is dead. This isn't news. It's often repeated and the story goes like this.
<p>
The hobby is full of old dying men who when they finally shuffle off this mortal coil, or as we like to say "become a silent key", will take their hobby with them. There is anecdotal evidence to back this up. An organisation that tasked itself with the preservation of Morse Code in the tradition of Telegraphers and Seafarers is forecasting their demise due to the age of their membership.
<p>
Other comments along these same lines talk about the futility of Amateur Radio in the face of other communication tools such as the Internet, Mobile Phones and the like. Emergency Services often ignore the Amateur Radio Service because they have all the communication infrastructure they need. People point at the declining numbers of Amateurs and say: "See, I told you, the numbers don't lie!"
<p>
If you listen to this you might wonder why it is that you're fascinated by this endeavour and what it is that these tales of doom and gloom for the future of our hobby mean for you.
<p>
Let's start with the numbers. In Australia in 2005 a new class of Amateur License was introduced. It's called the Foundation License and the purpose was to attract new people into the hobby of Amateur Radio. Looking at the numbers we see a year on year increase in the number of Foundation Calls. Many of those go on to gain extra responsibilities by getting a Standard or Advanced License. Some Amateurs let their Foundation Call lapse, so the increase of people entering is actually higher than a simple count of callsigns might suggest.
<p>
So, we're getting more and more people into the hobby every year.
<p>
But the overall numbers are declining. How can that be?
<p>
Well, simple really. We don't have a problem with growth, we have a problem with retention. This means that as a community we're doing great things about getting new people into our wonderful hobby but doing a poor job at making them feel welcome and keep coming back.
<p>
Those are numbers, but there are other things happening as well. The Internet today is a connection, actually an Inter-connection of networks. You might be surprised to learn that these networks started when we figured out how to use Morse Code on wires to send messages across the globe. While the original copper is probably not being used, though that in itself would be an interesting research project, the Internet today has its roots in the Morse Code driven Telegraphy network. The very first one of those was set up over 200 years ago in 1816.
<p>
There is a long history of explaining the relationship between wire Telegraph and Radio Communication, featuring long cats, dogs and a war between Austria and Prussia. Suffice to say that Telegraphy and Radio Communications both form part of a symbiotic relationship. It still does today. The Wired Internet and the Wireless Internet are the same animal dressed up with fancy technology.
<p>
Amateur Radio is the experimental arm of Radio Communications, so as long as humans want to communicate with each other we're here to stay.
<p>
Time and again, Emergency Services need operators in the case of an actual emergency and historically they have been drawn from wherever experienced bodies could be rousted, suffice to say, the Amateur community keeps on giving.
<p>
As for the old and dying men. Sure, we have some amazing history that senior members of the Amateur community have to contribute, with many lessons to be learned for the likes of young'ns like me, but I'm getting older every day and with me the rest of the population too. At some point we'll all be older and wiser, perhaps we'll even be Amateurs. Another way of looking at this is as the global population gets older with more free time on their hands, the more opportunities exist to introduce people into our hobby.
<p>
As for the retention. As a community we really need to investigate what it is that makes people leave, since that's where the growth of our community is working against our achievements to promote and encourage new entrants.
<p>
If you're not an Amateur today, I'd like to encourage you to investigate. If you are, then I'd like to encourage you to welcome new members, tell your stories and use your experience in this amazing hobby to share your excitement and sense of wonder. Perhaps consider if there is something you can do to help new Amateurs flourish in our community.
<p>
I'm Onno VK6FLAB
Listen:
Sun-Spots and Amateur Radio
Foundations of Amateur Radio
<p>
Amateur Radio as a hobby is one of those activities that covers a wide range of pursuits. A fellow Amateur once referred to it at 1000 hobbies in one. I like that as a description, but it really doesn't cover how wide and extensive this hobby really is.
<p>
You've heard me talk about radios and on-air activity, about contesting, about out door activities, about electronics and antennas, about the grey line and about decibels. Today I'm going to talk about the Sun.
<p>
Using a hand-held radio you're often using higher frequencies, 2m, or 144 MHz or higher. These radio waves mostly travel along line-of-sight. If you look at the lower frequencies, called HF, 28 MHz, 21 MHz, or lower, then those radio waves also travel line-of-sight, but they also travel up into the ionosphere surrounding the earth. If you manage to hit the angle just right, then some of those will reflect off the ionosphere back to earth.
<p>
It's a lot like skipping a stone on a pond. If you get it right, you might make it skip several bounces, if you get it wrong, it will go "plop" and vanish. The same is true for these frequencies.
<p>
One of the things that makes the ionosphere reflective to radio waves of a certain frequency is the level of ionisation in this area around the globe. Typically the ionosphere is somewhere between 50km and 1000km above you right now. At different heights the ionosphere reacts differently and the Sun shining on it will alter the properties as the day unfolds.
<p>
This is why when night turns into day and day turns into night, special things start happening along the border between day and night, the so-called grey line where it's not quite day and it's not quite night.
<p>
One way of looking at this is that the ionosphere heats up during the day. Now heat is an interesting thing. The Sun shining on your skin is experienced as heat, but what's actually happening is that the radiation from the Sun is exciting the electrons on your skin and you experience that as heat. As a matter of interest, the Sun generates about 650 Watts per square meter in the middle of the day coming through the atmosphere. That's about 650 Joules of Energy per second per square meter. Lots of excitement.
<p>
At the outside of the earth, there's about 1300 Watts per square meter. The difference, 650 Watts, is absorbed by the atmosphere.
<p>
So, the equivalent of the heat you feel on your skin is also heating up the atmosphere.
<p>
Now, this "heat" is really energy that's exciting electrons and thus also exciting the ionosphere. At the simplest level this is making the ionosphere more reflective to radio waves. I'm deliberately simplifying this because I don't want to get bogged down into how precisely, because my point is about the Sun and more specifically about Sun-spots.
<p>
There I said it, Sun-spots. What are they and what do they have to do with anything?
<p>
Well, a Sun-spot is a cool place on the Sun. When I say cool, it's about half as warm at a Sun-spot than the area around it, only 3000 degrees Celsius, instead of 6000 degrees. Sun-spots appear in pairs on opposite sides of the Sun and represent a point on the Sun where an intense magnetic field comes through the Sun. You can think of it as a huge race-track through the Sun that accelerates particles from the Sun into space. These particles represent energy and if they happen to hit the earth, they add a whole lot of extra energy to the ionosphere, making it much more reflective. The more Sun-spots, the more energy, the more excitement of the ionosphere, the more reflection, the better radio communications.
<p>
Sun-spots generally appear in groups and the density of these groups varies over time. To get a uniform sense of how much energy there is around, scientists came up with a Sun-spot number. It's indicative of how much activity there is, not an actual count of the number of dots on the Sun, since some spots are large and others are relatively small.
<p>
The increase and decrease of solar activity repeats over time. Using carbon dating we can get well over 11,000 years of solar activity which has lead us to say that we have a solar cycle that lasts about 22 years. Of course that isn't exact, since this is nature, but it gives us a simple way of better understanding a very complex topic.
<p>
The final bit of information you need is that when the amount of solar activity has peaked we have hit solar maximum and when it's hit the bottom, we have hit solar minimum. Since you cannot see those while you're in the middle of it, you can only really look back in time to determine what the exact point in time was that this occurred.
<p>
Another way to detect that we've hit a minimum is that the magnetic pole of a Sun-spot reverses. As I said, they come in pairs. One is the North Pole of the magnetic field, the other is the South Pole. When these reverse, that's an indication that we're starting the next solar cycle.
<p>
All that being said, it means that Sun-spot activity is strongly related to your ability to use HF over long distances and if you're a QRP operator like me, using 5 Watts to get around the globe, then you really want to know when the Sun is helping you and when it's taken it's bat and ball and gone home.
<p>
I'm not going to go into Solar Flares, Coronal Mass Ejections and the Solar Wind, since that's a whole new topic to cover for another day. Suffice to say that too much of a good thing is harmful to Radio Communications.
<p>
The Sun and the Solar-Cycle is an amazing topic that is just another aspect of our wonderful hobby of Amateur Radio.
<p>
I'm Onno VK6FLAB
Listen:
What does MARS have to do with Amateur Radio?
Foundations of Amateur Radio
<p>
In my travels along the highways and byways of the Internet I came across several references to MARS in relation to Amateur Radio. Being the curious soul that I am, my interest was sparked. I must warn you, today there is a lot to cover.
<p>
First up before I tell you anything, let me start by pointing out that what I'm talking about has different levels of application depending on where you are on the planet. I also need to inform you that in some parts of the globe this is considered illegal, where in other parts of the same globe, it's perfectly fine.
<p>
So, MARS, or MARS/CAP if you want to get more precise. What is it, how does it work and what do you need to know about it?
<p>
MARS is an acronym for Military Auxiliary Radio System and CAP is an acronym for Civil Air Patrol.
<p>
Given that we don't have such things in Australia, this phenomenon relates to the United States of America where MARS/CAP is used to coordinate search activities and relay messages on HF and VHF frequencies near Amateur Bands. As an interested party you can join up, do training and participate.
<p>
That aside, the term MARS/CAP is more widely referred to as a way of modifying your radio to allow it to access to frequencies outside the Amateur Bands. Now at this point if you're a licensed Amateur your ears should have pricked up when you heard the words "modifying your radio" and "outside the Amateur Bands". This is as I already said, legal in some parts of the globe and not in other parts.
<p>
So, a MARS/CAP modification extends the frequency coverage of your radio. Some modifications involve extending what frequencies you can receive, others extend the transmit frequencies. Often these changes are separate, but not always, so make yourself aware of what you're doing before you do anything.
<p>
Now why am I telling you about something that some might consider shady or illegal? First of all, I've not actually told you what to do or how to do it. Second, if you're trawling through the Internet and you come across such a thing, how would you know what it means in your situation, other than a list of instructions shown on some random website?
<p>
There are several different aspects to this. As I mentioned, the legal aspect which I'll discuss a little more later. There's also the technical, performance and warranty aspects to consider. Not to mention, emergencies and other exceptions.
<p>
From a technical perspective, there are generally two types of MARS/CAP modifications. There are hardware ones where you pull out your soldering iron and modify the circuit on your radio by adding or removing something. There are also software modifications where updating the version of the software on your radio, or changing a flag, or setting a memory will make the modification. The hardware changes are generally pretty permanent, the software ones are often able to be reverted back to normal, but not always.
<p>
While I'm warning you, some radios when opened up reset their memories, so you may need to reprogram all those channels when you put it back together again.
<p>
Now, your Amateur Radio is a finely tuned animal. It's specifically configured to work within the specifications of the Amateur Bands and regulations and as you should know, there isn't a single piece of hardware that exists that isn't subject to the variation of its components. This means that if you compare two identical radios, the same batch, the same builder, they still are not identical. If you put them on a testing bench, you'll notice subtle differences. They'll be close, but not the same. Each one is specifically set with preferences, variable capacitors, inductors and resistors to respond just so, and meddling with the hardware or software can - and likely will - change this finely balanced piece of gear. If you're fiddling to fiddle, be aware that you might never get your radio back to the way it was before you changed it.
<p>
If you let the magic black smoke out of your radio and return it to the manufacturer for a warranty repair, be prepared for a rejection letter or a hefty bill if you make any modifications.
<p>
So, on the no side, there are lots of things to consider.
<p>
On the yes side, there are others.
<p>
In the case of an emergency all is forgiven. If you need to call an emergency on some random frequency, then that's fine, but make sure it's a real life threatening one. If that's the case, does that mean that you need to carry a soldering iron around or a computer with a piece of software to reprogram you radio when that emergency hits?
<p>
Another thing is that many Amateur Radios, including the one sitting on my go-kit, a Yaesu VX-7R has a receive range of 500 kHz to 1 GHz with a few little gaps to exclude some mobile phone frequencies. There is no need to do any modifications to receive anything, just to transmit.
<p>
There are many websites dedicated to MARS/CAP modifications and for some people these are perfectly fine, but you won't find much in the way of disclaimers on those sites, nor will you see much in the way of warnings. You might have just modified your radio because you're curious, or you might have thought about doing so. Now you know a little more about the implications.
<p>
I did say that I'd come back to the legal side before I finished.
<p>
Here's a curious thing.
<p>
Essentially for commercial radios, the radio is licensed and for Amateur Radio, it's the person. In Australia, if I have a commercial radio that is approved for use on specific commercial frequencies, it's perfectly legal to modify that radio to use it on Amateur frequencies. But if I have an Amateur radio, it's not legal to make it work on commercial frequencies.
<p>
If that doesn't make your head explode, here's another passing thought. If you have an entirely Software Defined Radio that's approved for use on commercial frequencies, then what's the difference between that and the same radio approved for Amateur radio use, if the only difference is limits on the user screen access?
<p>
My point is that the law hasn't yet caught up with radios that work on any frequency. When it does, it's likely that the almost arbitrary distinction between commercial radios and amateur radios will disappear and your Amateur License will determine what is allowed and what is not.
<p>
A burning question you might be left with is: "So, Onno, did you modify your radio?" and my answer to that is: "Nope". I don't know enough about what these changes will do to the actual performance of my radio, if it introduces crazy harmonics and how I'd test for that, nor do I know what the precise legal implications are for me personally.
<p>
What I do know is that much of this is never talked about, let alone debated with any level of professionalism and frankly I don't think that's good enough.
<p>
These modifications exist, sometimes they're trivial to do, but the community pushes the implications under the rug and says: "Don't look here, there be dragons."
<p>
I for one think that Amateur Radio should be leading the way in this discussion, not hiding from it.
<p>
I'm Onno VK6FLAB
Listen:
A nifty idea looking for a purpose in 1947 changes the world as we know it...
Foundations of Amateur Radio
<p>
If you have the need to switch something on and off, a likely first candidate is to get a switch from the local hardware store. The principle is pretty straightforward. You put the switch into the power supply lead and by pushing it on, the two halves of the switch make contact with each other, completing a circuit, and the thing you're switching turns on. It's a lot like having two bits of bare wire that you can touch the ends together.
<p>
What if you want to remove the human touch from the equation, that is, switch something without having to actually push a switch? A potential candidate for this is a relay. In essence it's exactly the same as a manual switch, except the pushing is done by an electromagnet. The way it works is that you send a current through a coil that is wound around a metal core which results in a magnetic force. This force is used to push or pull the switch open or closed.
<p>
Now both a manual switch and a relay have moving parts. That means that there is a limit to how fast you can switch something on and off. You can probably push a manual switch several times a second, lets say 10. So the switching speed is called 10 Hz. A relay can likely get you switching around 100 times per second, or 100 Hz, but if you want to switch something at a much higher speed, say at 1000 Hz or more, some other form of switching comes into play.
<p>
At its simplest, a transistor is like a relay without any moving parts. There's no actual switch, no coil, no electromagnet, none of that. Without going into the physics of how this all works, let's look at an analogy. Imagine a water-pipe with a valve on it. You can open or close the valve and water flows or not.
<p>
In a transistor, the same principle applies. There are three legs, two of them act as the water pipe, the third one acts as the valve. You open or close the valve by putting a current onto the valve - or base - leg and a current flows between the other two, the collector leg and emitter leg.
<p>
Now, so far I've just told you that you can open or close a transistor with a current, but it's actually more nifty than that. You don't need to have it all on or all off. In our water pipe you can set the valve to any setting and control how much water flows. In a transistor you can do the same by changing how much current you put onto the switching or base leg.
<p>
You might have heard a description that says that a transistor is both a switch and an amplifier. If you haven't don't fret, I'll explain. Let's go back to water for a moment.
<p>
Imagine a huge water pipe connected to a dam. Lots of water all pushing into our water pipe. The valve we have can be controlled by you blowing water through a straw into the valve. The more water you blow into the valve, the more water flows out of the dam through the pipe.
<p>
If you blow hard into the straw, the result is a wide open valve and lots of water from the dam, if you blow softly, less water. In essence your little water flow from your straw is being amplified by the dam.
<p>
A transistor works just like that. As I said, you don't have to use a transistor just to switch something completely on, or completely off. If you vary the current into the base, you can vary the amount of flow between the collector leg and emitter leg.
<p>
The current you use to control the flow is tiny, so you can use a really weak signal to control the thing. In essence that's how a transistor radio works. The small signal that we use to control the flow is the tiny one coming from an antenna, the dam is the battery and the speaker is connected to the output. So, a small electrical current coming from the antenna controls the transistor which in turn controls the amount of current coming from the battery onto the speaker.
<p>
A hearing aid also works in the same way. A small current coming from a microphone controls the transistor which in turn controls the amount of output from the battery to a speaker.
<p>
The reason I mention transistor radios and hearing aids is because that's how the invention of a transistor in 1947 was popularised, since it was seen as a nifty gadget in the days of valves with little application in the real world.
<p>
Since then, we've combined billions of transistors into chips that we use daily to see what time it is, what the weather is like and to write emails, control rockets, save lives and do all the things we take for granted in our electronic world.
<p>
The transistor is an example of a nifty idea that you may think of as being a difficult concept, but in reality is not that hard. Don't get me wrong. There are many different types of transistors, each with different characteristics and limitations, the physics don't work like water, but knowing the basics of how it works will be sufficient to get you on your way.
<p>
I'm Onno VK6FLAB
Listen:
Beauty is in the eye of the beholder ...
Foundations of Amateur Radio
<p>
Beauty is in the eye of the beholder. I look at an antenna and marvel at what it implies. A simple piece of conducting material made into some particular shape and size that harnesses the radio spectrum. I find it fascinating that this can and does exist and my fascination translates into a thing of beauty.
<p>
I recall being on a camping trip and being introduced by a friend to an antenna that was strung between two trees in the middle of the bush. For some reason that escapes me we needed to lower the antenna and I got to have a look at the feed-point.
<p>
Let me describe this to you.
<p>
Picture a ceramic fence insulator. The two legs of the wire dipole are each fed through the insulator at a 90 degree offset, in just the same way as you would install it into an electric fence. Looped around this is a piece of RG213 coax which is soldered onto each leg of the dipole, shield to one side, centre to the other. No traditional balun, but there is a piece of wire wrapped around the coax, holding it all together and I have no doubt that it acts as some form of choke.
<p>
This thing looks absolutely horrible. It's weathered, it's rough, it's nasty, has spider-webs and other little critters living in the insulator, the soldering is quick and dirty, the shield is roughly attached to one of the legs. If you've been in the Australian Bush and visited a farm there you'll know exactly how rough and ready this antenna is. I seem to recall that its proud owner (Hi Kim) put it up temporarily in a hurry to get on air one day, a decade or so ago.
<p>
So, what of this ugly mess?
<p>
It was the best antenna I've used in a long while. It allowed me to make my first QRP contact across the length of Australia into New Zealand. It allowed me to contact the 7130 DX net for the first time and we talked to a globe circumnavigating sailor on this antenna.
<p>
So, as ugly as this thing is to look at, from an antenna perspective, it's the most beautiful thing I've seen in a while.
<p>
Now, you need to know something. I saw this antenna nearly four years ago. I have photos of it. Every now and then I go back to those photos and marvel at it.
<p>
In our hobby we have people from all different walks of life. It's been pointed out on more than one occasion that as a community, the single piece of glue we have is our Amateur License. Of course some of us have more in common than just that, but it would be smart to remember that every member of our community has a different view on aesthetics, a different perspective on what is good and what is bad.
<p>
I recall coming into a new radio club, I had been an Amateur for less than a month, and bringing along my shiny new Yaesu FT-857d, I was so proud of my acquisition. It was everything I liked in a radio. I'd bought it with hard-earned cash and I was chuffed to show it off. One of the first comments I received was: "Well that's an ugly radio!". Suffice to say that I was unimpressed with that assertion. Their perspective was based on their love of the FT-897, which has a different shape, one that didn't particularly appeal to me.
<p>
Since that experience I've attempted to subject myself to many different radios. It's become apparent to me that everyone has a different thing they like about their radio. For one it's the layout, for the other the filters, another likes the colour, the price, the number of buttons, the history, its power consumption, the brand, the whatever.
<p>
Each to their own.
<p>
I'm pretty sure that I'm also biased. I recall at least two instances where friends of mine purchased a radio that I would not have considered since they lacked a particular feature that I felt was essential. I'm not sure I was gracious in my assessment of their new purchase, but I hope to make amends.
<p>
In some workplaces there are policies of tolerance in place. There is an assumption that people are going to be together in the same place for long stretches of time with different cultures, different outlooks, needs and desires and different life perspectives. Some employers have attempted to codify this into a workplace diversity policy.
<p>
It occurs to me that in Amateur Radio, our attempt at doing such a thing is outlined in something we refer to as "The Amateur's Code", written in 1928 by Paul W9EEA. The language is a little stilted, reflecting its origins, but it's an interesting take on what it is to be an Amateur.
<p>
If you've never heard it, let me share with you the words written by Paul. I should add some disclaimers about gender and country here, but I'll leave the text as it was.
<p>
The Radio Amateur is:
<p>
CONSIDERATE, never knowingly operating in such a way as to lessen the pleasure of others.
<p>
LOYAL, offering loyalty, encouragement and support to other amateurs, local clubs and the American Radio Relay League, through which Amateur Radio in the United States is represented nationally and internationally.
<p>
PROGRESSIVE, with knowledge abreast of science, a well built and efficient station, and operation beyond reproach.
<p>
FRIENDLY, with slow and patient operation when requested, friendly advice and counsel to the beginner, kindly assistance, co-operation and consideration for the interests of others. These are the hallmarks of the amateur spirit.
<p>
BALANCED, Radio is an advocation, never interfering with duties owed to family, job, school or community.
<p>
PATRIOTIC, with station and skill always ready for service to country and community.
<p>
I'm Onno VK6FLAB
Listen:
More strange antennas!
Foundations of Amateur Radio
<p>
About ten minutes ago I was blissfully unaware of the existence of James K2MIJ. It's unclear if this bliss will ever be returned because it's obvious to me that James and I share several things, a sense of humour among them. Mind you, I've not yet actually spoken to James, other than me saying "Hello" right now, but his QRZ page is a thing of wonder.
<p>
Last week I was talking about weird and wonderful antennas. As you know, Amateur Radios don't particularly care what you plug into the back, as long as it looks like a 50 Ohm load, the vast majority of transceivers will happily transmit into them. I've heard of people making contacts with dummy loads, bits of wet string, chairs and as I said last week, bridges and rail-road tracks.
<p>
James has made it his mission to tune up strange things. He's made a lawn chair dipole and is using it to contact all states across the US, with only 5 Watts. He's added more countries to his DXCC than I have - 53 - and while he's at it, he also made some other contraptions, a fork dipole, from two actual kitchen forks, his in-the-shack dipole and his latest contraptions, a collection of five and a half inch and nine inch antennas. You heard that right, a five and a half inch antenna for 40 meters.
<p>
If you go to James' QRZ page, you'll find a kitchen table, holding an antenna farm that rivals those of many stations. Antennas for 40, 30, 20 and 17 meters.
<p>
One thing that piqued my curiosity is a photo of his 20m antenna sitting on the ground. Picture something like a peanut butter jar lid with a piece of copper stuck in the middle, standing up. It's wound around in a spiral with two windings, sort of like a big loading coil you'd find on a 2m vertical antenna.
<p>
The base of the contraption has about 30 or so windings on it which you connect between the copper and the feed-line.
<p>
The thing that got my interest was what was on the other side of the feed-line, a tape measure. More precisely, a steel tape measure.
<p>
As I said, I've not yet spoken to James, but it might be that his mini-antenna is mostly made of tape measure. Don't get me wrong, I think experimentation is wonderful and he's clearly made more contacts that I have, but I'd love to learn what effect the tape measure has on his contraptions.
<p>
I noticed a few other things that people have tuned up, beer cans, especially helpful with Fox Hunting, when one of your friends, or should I say Fiends, sets up a secret transmitter that you and several teams have to track down. The more devious the antenna installation, the better.
<p>
There's the quintessential flag-pole antenna for those times that your neighbours need to see that you're patriotic and not a nasty radio amateur with unsightly antennas that reduce the value of their home and remove the enjoyment of their life because your hobby affects their ability to sleep at night.
<p>
I've seen people tune up their gutters, even tried it myself - the noise floor in my shack prevents anything sensible, but I'm working on it - and of course there's the proverbial boat on a trailer antenna. No interest in sailing as such, just a nice tall aluminium construction that could perhaps be connected via some feed-line to a nearby radio transmitter. It's not even a permanent structure, so it'll add value to the neighbourhood.
<p>
Making a weird and wonderful antenna as an experiment is great for learning, it's great for experimentation and dealing with emergencies and it might keep your neighbourhood happy too - mind you, why anyone would think that an antenna is ugly is beyond me.
<p>
I'm Onno VK6FLAB
Listen:
Tuning up strange antennas ...
Foundations of Amateur Radio
<p>
During the week I received a funny picture from a fellow amateur. This particular image was one titled "Multitap Antenna" and it featured a Four Wheel Drive vehicle with a bull-bar and a spring base mounted antenna. The antenna was made from pipe and at suitable intervals the pipe had a t-piece with a tap.
<p>
Nothing too peculiar, right? Well, other than that the taps were standard brass garden taps with a hose-quick release clip and hose fittings.
<p>
Made me laugh.
<p>
Anyway, that reminded me of a series of postings on Social Media about the random things people have used as antennas, from emergency bits of copper wire attached to flag-poles to get a local station back on the air during an emergency to tuning up wire fences, bed frames and the like.
<p>
There's even a "Strange Antenna Challenge" with suggestions of ladders, baby chairs - presumably without the baby, umbrellas in trees and other fun stuff. Suggestions to contact your local TV station to promote the activity to bring back some fun into Amateur Radio.
<p>
Now, why am I even talking about this?
<p>
As Amateurs we take ourselves very seriously, so seriously that any idea that isn't following the norm is scoffed at. "This is how we do things around here" and "That will never work" are often heard in group discussions among the knowing elite of Amateur Radio.
<p>
Here's the thing.
<p>
We're Amateurs, experimenters, licensed to test, to play, to learn.
<p>
What if you find yourself on the side of the road with an up-side-down vehicle with a perfectly working radio, but a broken off antenna? What would you do? What if a storm blew your antenna down, or it was destroyed by a flood? How would you cope? Would you bring out your trusty spare antenna and plug that in, or would it be helpful to have some experience with tuning up weird stuff and seeing what happens?
<p>
For my money, I'd rather know an Amateur who can make the proverbial wet piece of string work, than the one who has the latest gadgets and gizmo's ready for that day that the emergency arrives. Hopefully their spare antenna will be in their car and not sitting in the Garage waiting for the emergency to arrive at the right time and place.
<p>
So, if you did in fact have some fun and started playing, some of this is going to fail and some of it will work poorly and some of it won't work at all and you might damage your radio if you pump full power into a random piece of conductive material, but, you might also just come across some skills that you could use when it becomes essential, or when you're up a creek without a paddle.
<p>
So, when you've done everything and are looking for the next challenge, have a look at the Strange Antenna Challenge, there's been activity going back over a decade featuring two cars as antennas, rail road tracks, a bronze statue, exercise machines, a football stadium and a bridge.
<p>
The only requirements are that no wire and no metal pipe allowed.
<p>
Remember to take a photo of your contraption, so you can share your adventure.
<p>
I'm Onno VK6FLAB
Listen:
Do we really understand our hobby?
Foundations of Amateur Radio
<p>
Today I was going to talk to you about Grid Dip Oscillators. Some research later I realised that I don't yet understand the topic enough to explain it to myself, let alone explain it to you. I then set my sights on a simpler thing, an SWR Meter.
<p>
Pretty standard fare in a radio shack. You plug it in and off you go, nothing to it.
<p>
So I then set about learning how this actually works. As you know, if it's written on the Internet, it must be true, and in this case, there must be a thousand different explanations and ways that this common black box works in your shack. Since I found so many different explanations that made me recall a quote:
<p>
"You do not really understand something unless you can explain it to your grandmother."
<p>
So, at this point I should sit down and explain it to you as if you're my grandmother, right?
<p>
Unfortunately I'm not yet at that level of understanding, so I'll not add to the noise of explanation until such time as I do understand it. Instead I'm going to take a left turn and observe that Amateur Radio is full of explanations. Some of them great, many of them horrendous.
<p>
I see Amateurs on-line arguing about how something works and then I hear them on-air doing more of the same.
<p>
It occurs to me that where ever there is argument about how something works there is one of two things going on, lack of knowledge or lack of understanding.
<p>
I'm not saying that every Amateur doesn't understand, I'm wondering if it's possible that our collective understanding of how our hobby works appears to be lacking in scientific rigour and that it's incomplete. I'm wondering how much of our hobby is actually understood and documented.
<p>
While I'm here, I should point out that taking observations of a phenomenon isn't an explanation of how it works. The observations will get you places, but the unexpected or unobserved might get you killed along the way.
<p>
I've said in the past that this hobby is like Magic and I still think that. The more I learn and understand about it, the more Magic comes in to play. This is what keeps drawing me back to this wonderful world of Amateur Radio.
<p>
While I was searching for my SWR explanation I came across this little gem which speaks to me greatly and goes a long way to explaining why some of our hobby is so misunderstood:
<p>
"the reason that your friends and ours cannot understand mathematics is not because they have no head for figures, but because they are unable to achieve the degree of concentration required to follow a moderately involved sequence of inferences"
<p>
So, next time you sit down to explain how something works, bear that in mind, since following along a string of things that lead to an explanation might not be something your, or my, friends are willing to put up with.
<p>
I wish I'd seen that quote before I attempted to explain why I had several antennas on the roof and couldn't just have one.
<p>
Still learning...
<p>
I'm Onno VK6FLAB
Listen:
SOTA goat adventures ...
Foundations of Amateur Radio
<p>
Last week I went on an adventure and came home with an experience. I've been wanting to go out and play radio for a while. Work has been spectacularly unhelpful in making time available to achieve this, not to mention the 17 million other things vying for my undivided attention.
<p>
Last week the planets aligned and my outing came to pass.
<p>
I'd set my sights on doing a SOTA activation. If you're not familiar with that, SOTA is an acronym for Summits On The Air and the aim is to get to the top of a mountain and make contacts from there. I've previously been under the tutelage and presence of some very experienced SOTA hams and during a conference in Canberra last year I managed to activate several summits with others.
<p>
I even managed to survive walking up one peak on my own, using my hand-held to make some contacts. I use the word survive in less than ironic terms because I relied on Google Maps to navigate me up to the peak and for reasons best known to Google, it walked me up the side of the peak that didn't actually have a track, even though the map was adamant that I should follow the path. Many, many hours later, not properly dressed, not enough food, weather coming in, batteries running low, I managed to get back down safely and hobbled to a taxi who brought me back to my hotel. It was memorable, but not for the right reasons and it didn't involve HF communications and at the moment I'm struggling to recall if I actually logged those contacts. That will be a job for another day.
<p>
Anyway, as I said, the planets aligned and I had a day to myself, access to the car, a charged radio battery pack, a working antenna and a map that worked. Mind you, I spent an hour fighting technology. First to register on the SOTA web-site, then to activate the software on my phone, then to get Google Maps to actually navigate me to the peak and for it to download the off-line maps, so I could navigate whilst out of mobile phone range. Lesson learned, plan to do the technology before the day.
<p>
So, I set off an hour later than planned, but I was finally on my way. Google Maps again let me down by navigating a different route than I wanted, since I had the choice of more or less dirt road and I wanted less. Google picked the other one, even though I pointed it at the one I wanted. Another lesson learned, make sure that you add markers to your route before Google Maps starts you on your way, since there is no changing it once you're driving.
<p>
After an hour and a bit I arrived at the top of the peak. If you're interested, it was Mount Dale, or SOTA peak VK6/SW-036, but before you go looking for my log, stick around, there's more to the story.
<p>
So, I set-up my antenna, a multi-tap Outbacker and set it to 40m. I appeared to have mobile phone coverage, so I added my spot to the SOTA-watch website and started calling CQ. I managed my first contact within 8 minutes of my advertised time start time, so I was pretty chuffed.
<p>
For the next few hours on 40m and 15m I managed contacts with 23 stations. The biggest distance I managed was 5353 km, or 1071 km per Watt. Not bad for a vertical antenna mounted to my car.
<p>
I did some experiments along the way with turning my car around, getting better and worse signals, but overall it was great.
<p>
I had a little play with 2m, but didn't manage anything other than talking on the local repeater, which is located 24 kilometres away and about 250 meters lower down. One friend suggested that there was a satellite pass coming over later in the day, but by the time I'd been there for four hours I was cooked. It wasn't spectacularly hot or anything, but it was time to go. No satellite this time, but something to add to my list of things to check.
<p>
I came home and basked in the enjoyment of having gone out and made contacts, more than I'd managed for most of the year. Very satisfied.
<p>
The next morning I found an email from the SOTA manager in VK6 who asked me about my operating environment. After some back and forth it was determined that I should have read the rules before going on my trip. If I had I'd have known that I couldn't operate from within my car, nor could I operate with anything attached to the car. In later discussions one person said that the guideline they used was that if someone drove the car away, would they still be able to operate their station. It seems even shade from the car is frowned upon. So, another lesson learned, read the manual before going outside.
<p>
In my discussions it emerged that my trek did qualify for WWFF, or World Wide Flora and Fauna where the rules are different. Of course I've not yet read those rules either, but you know, radio. I should point out that the local Flora and Fauna group is called VKFF.
<p>
So.
<p>
I swallowed my pride, sent an email to the SOTA email list and posted on the SOTA group to tell my contacts that I wasn't able to submit my contacts as valid SOTA contacts, but that I would be cherishing their contact in my log.
<p>
I've not yet sent off my log to the local WWFF coordinator, work has managed to stymie that effort, but I have the log and I'll send it off when I have a spare hour to enter the contacts into a computer and format them as required.
<p>
So, from a lessons learned perspective I managed to get to the top, set-up my radio and make contacts. That's a great outcome. I have been out when that didn't happen.
<p>
I also learned that Google Maps, something which I use almost daily, is still trying to kill me, it's just being more subtle about it than I would like. I'm sure that there's a reddit writing prompt in there somewhere. Perhaps I'll write it in my munificent spare time.
<p>
I should read the rules for both SOTA and WWFF and I need to figure out how I'm going to be portable with my radio bolted into my car. I really don't fancy pulling it out and I'm not in any financial position to go out and purchase another radio, though if you're feeling inclined, you're welcome to make a donation to my benevolent fund - the Donate button is on the podcast website.
<p>
On a more serious note, I did receive an email while I was on the top of Mount Dale from a listener who was freaking out that they were listening to me on last week's podcast and saw my callsign on the SOTA cluster, so I replied by telling Brian, AF7MD, that I was still on the mountain. He hasn't replied yet. I hope he's OK.
<p>
I did get lots of other emails from well wishers for my First Solo SOTA effort, so thank you for your messages of support. Sorry I let the side down by making an invalid activation as my first effort.
<p>
So, I think the message should be that SOTA can be fun, it can be rewarding and you can make contacts with 5 Watts, but you need to read the rules and prepare the day before you plan your outing.
<p>
I'm Onno VK6FLAB, not quite a goat yet.
Listen:
Passion and Politics
Foundations of Amateur Radio
<p>
Today I want to talk about Politics. I can hear you groan from here, so hold your horses, stow your tar and feathers and put your pitchfork back in the barn.
<p>
Amateur Radio is a hobby. It's to do with electronics and physics and the ionosphere and other cool stuff. Some people call Amateur Radio a thousand hobbies in one and that's a pretty good description.
<p>
Underlying Amateur Radio are the people. Those who have spent their time studying, learning new skills, doing tests, passing exams, as well as people who are interested bystanders, not necessarily licensed, but drawn towards the bounty that Amateur Radio as a hobby represents.
<p>
An interesting phenomenon among people is their varying level of passion. Some people are passionate about their dog, others about their children, others are passionate about cars, or baking, or in our case, passionate about Amateur Radio.
<p>
Passion has been explained to me once as a "big elephant". You sit on its back and it takes you where you want to go. Gentle nudging makes the elephant change direction, but if it gets excitable or startled, it'll go where ever it wants and all you can do is be a passenger and hold on tight.
<p>
If you mix passion and Amateur Radio, there are times when that will result in heated discussion about the merits or pitfalls of a particular radio, an antenna or some other aspect of the hobby.
<p>
If you group people together into radio clubs then those clubs are made of passionate individuals who come together to promote the objects of their club. As people group and discuss, opinions differ, goals morph and change and aims and objectives are blurred.
<p>
Before long, you get special interest groups, proponents and opponents, elections, board meetings, stoushes, mis-management, legal action and the whole gamut of life.
<p>
To complicate matters, Amateur Radio uses a public resource, radio spectrum. This is generally managed and maintained by a regulator, which in turn is generally managed by, politicians.
<p>
What this means is that as a Radio Amateur you should not be surprised to learn that politics plays a part just as it does in the rest of society.
<p>
I can still hear you muttering from here. My In-Box hasn't yet seen any derisive emails, but I can picture their arrival.
<p>
What does this all mean?
<p>
It means that Amateur Radio is not one thing. It never has been and never will be. For each individual there is a personal path to find and a journey to travel. For some this means that they'll become the Contester of the Year, for others it means that they'll invent a new gadget, others will use Amateur Radio as an excuse to travel the globe and others will use it to be the big cheese in their club.
<p>
Your role is simple.
<p>
Remember that this is a Hobby. That it's your hobby and that you have as much say in it as the next person.
<p>
Remember also that this Hobby exists because we've been given access to a public resource and it's our responsibility as Amateurs to conduct ourselves in a manner that befits that public trust.
<p>
I'm Onno VK6FLAB
Listen:
Coax vertical dipole and other musings ...
Foundations of Amateur Radio
<p>
The other day I celebrated my sixth birthday, no not that one, the one that reminds me when I first became licensed as a Radio Amateur. It caused me to reflect on what I've done with my license and what I've learned and where I'm heading.
<p>
A recurring theme in my Amateur life is one of upgrading. Not a month goes by when someone makes a comment about my license status. As you might know, I hold the entry level license in Australia, the Foundation License as it's called. Other countries call theirs different things, but the aim of this license type is to introduce new entrants into the hobby and for me it's done that in spades.
<p>
If you've listened to some of my previous mutterings and musings, or if you've listened to all of them, heading for 300 now, you'll have noticed that it's rare that I'm not talking about something I learned, something new, or something that interests me that I've found and I want to share with the community.
<p>
This quest for knowledge, learning and curiosity is something that I've always had and I'm sure I'm not alone with those traits. It occurred to me that my newly minted Amateur License achieved exactly what it intended to, Introduce me to Amateur Radio. It did more than that. It set me on a path that I'm travelling down today where I'm learning a new thing most weeks and telling others about it.
<p>
I don't yet fully grasp the difference between an NPN and a PNP transistor, nor do I understand the workings of a Valve to the point where I can explain it to you, but the truth of the matter is that I haven't had the need to, or at this stage the curiosity to. That's not to say that a day will come when I do want to know.
<p>
So here's the thing.
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Would you rather I have the highest level of license, having passed my test, cramming for my exam, guessing answers on a multiple-choice form, or would it be better if I came to know and understand the body of work that makes up the foundations of our hobby? As an aside, I have taken a mock test at some point. If I recall, I managed a score of 75% or so, might have been higher, but it outlined the areas of knowledge that I don't have at this time and that was why I took it in the first place.
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There are Amateurs who pass tests and then there are Amateurs who learn.
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One final comment about upgrading. When was the last time you upgraded your car license to the next level, say rally driver, or Formula-1 driver? When was the last time you got called out on not having upgraded and admonished for being a lowly car driver?
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Onto Amateur stuff.
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First of all, the wheel bearing has gone to a better place. It drove away on a big blue truck on Wednesday morning and is no longer. So sad.
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In antenna news, you may recall my experiences with the installation and tuning of an antenna for a friend of mine. I made all manner of what some would call outlandish statements, one Amateur all but called me a liar and accused me of making it all up to promote my podcast. All this excitement because I dared query the documentation of an Antenna. I've reached out to the manufacturer, but I've not yet received a response.
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I'm told that my hunch that this was a vertical dipole was correct. That in itself is curious since I've been experimenting with a vertical dipole made from coax, not enough to talk about success yet, but enough to be told that it will never work. Gotta love the doubters. As I suspected, the cut-off piece of inner coax, if you recall, the one that was a centimetre or so too long, is half of a capacitor, the other half is in the base of the antenna.
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Note that all this is based on what I've been told by a fellow amateur, and I'm looking forward to hearing from the manufacturer what they have to say.
<p>
So, my vertical coax antenna idea started off with the idea that I wanted to use a vertical dipole for working portable. I realised that some of the designs I've seen knocking around the 'net are cutting off long chunks of shield, or folding it back, or doing all manner of funky things to a piece of coax. I wondered what would happen if I took a piece of wire, cut it to the length of one half of a dipole, attached a banana-plug to it and stuck it on the end of a piece of coax.
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One half of the antenna would be the wire, the other half would be the shield of the coax.
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If I could come up with something like a choke that would stop RF travelling all the way back to my radio, I might have myself a vertical dipole with the benefit of not having to cut up coax, no extra connectors and if I made it possible for the choke to slide up and down, my antenna would be simple to transform into something for any band.
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As I said, I'm not yet at the success stage. I did some testing with something called an ugly balun, but it's pretty clunky and results are mixed. I tried ferrite-clip-on-beads, but they didn't seem to do the trick - though that could have be the nature of the particular clip-on's that I had at the time.
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When I have some more play time free, I'll have another crack at it, since it seems promising and if there are people selling vertical dipoles with curious matching networks at the base, there's hope for me yet.
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I'm Onno VK6FLAB
Listen:
Manufacturer drivel and antennas ...
Foundations of Amateur Radio
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Let me start completely off-topic today with a thank you for emails and other expressions of concern regarding the demise of the bearing last week from my messy desk. I did not loose my marbles, other than the ball bearings in the disposed item and my sanity is as intact as it ever was. I was also asked for photos of the messy desk and as a concession to that I'll use a photo of the ball bearing for the podcast edition this week.
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How am I able to produce a photo of the disposed ball bearing? Truth be told, it's in the bin, the bin is in my office, but it wasn't emptied last week, since there was so little inside, so the ball bearing lives - until Tuesday when the bin will surely be emptied.
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Now, on to Amateur Radio matters, since that's why I'm here, though based on your emails, I'm not quite yet sure why you're here.
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Yesterday a good friend of mine, who tragically has yet to see the light and become a licensed Amateur came to me with a non-functioning antenna. He had purchased a so-called "Ground Independent Monopole" suitable for 380 to 520 MHz. You get no points for guessing that this was to be used for a CB installation on his vehicle.
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When you read the accompanying material, this magical antenna has a 4 dB improvement when compared to a 3 wave whip in the centre of a metal roof. But then when you look at the foot note, it talks about a 4 dB improvement over a 1/4 wave whip, but pattern tests only deliver a 2 to 2.5dB actual gain.
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I can hear you groaning from here. It leads me to several observations.
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As a licensed amateur you should be able to already spot holes as wide as a semi-trailer in those few statements. As amateurs we're often dismissive of the CB community, but how can they be held to account if manufacturers publish what looks to me like drivel of the highest order.
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The design itself is curious. There appears to be a loading coil in the base, the centre of the coax is trimmed to a specified length and inserted through the coil and electrical continuity exists between the radiating element and the coax shield.
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After spending some time trouble-shooting the installation I determined that the PL259 connector at the end wasn't actually soldered to the coax, so we fixed that. Using my antenna analyser we trimmed the vertical as specified, a couple of millimetres at a time, but it wasn't setting the world on fire with the updated SWR charts I was generating.
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We stopped trimming when we got close, since cutting off length is easy, cutting on length not so much.
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I then re-read the instructions and queried the length of the trimmed bit of inner coax that was inserted into the loading coil and found out that it was about a centimetre too long. Fingers crossed we trimmed that to length and the SWR chart improved. It still didn't set the world on fire, but at least the SWR wasn't 8 to 1 on CB Channel 40.
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Of course I've urged my friend to get an Amateur License, but that's ultimately their own choice.
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What I took away from the experience is that even a very basic Amateur License like the one I hold is sufficient to understand better what is going on and to be able to begin the process of trouble-shooting antenna installations.
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I thought I understood that this antenna was basically a vertical dipole, but at the moment I'm not sure and I'm wondering if the loading coil is actually a matching circuit and I wonder why the coax shield and the radiator are connected to each other.
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I'm sure the antenna is designed with the best intentions and I'm moderately confident that it works as intended. Now all we need to do is train the marketing department to talk to the engineering department before publishing their materials.
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For me the take-away is two fold. Don't blame a CB-er for their lack of knowledge, sometimes the manufacturer is to blame. The other take-away is that with a basic understanding of Amateur Radio you can help your fellow radio operator.
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Now, where on my desk is that thing I was looking for?
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I'm Onno VK6FLAB
Listen:
Messy shacks are the way we do things around here.
Foundations of Amateur Radio
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In my time as a member of the radio community I've been in around 30 different shacks and a similar amount of camp-out style activations. I've operated at least a hundred different radio set-ups with different operating styles, logging systems and power sources. I wouldn't say that I was particularly experienced, but I've seen enough to make some observations.
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My first observation is that radio shacks and set-ups tend to be messy. It's not unusual to see several radios, antenna tuners, amplifiers, switches, computers, power supplies, soldering iron and accumulated cruft in the form of resistors, wires, spare antennas, connectors, screws, knobs and globs of solder, all vying for space on the same bench at the same time.
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I'm looking at my own desk right now and I can count a hundred different objects within 60 seconds with no effort what-so-ever, and that's on a desk that's barely larger than a square meter in size. I'm not particularly messy in the scheme of things. There's no food on this desk - other than the cup of coffee I've just made and there's no globs of solder or other sticky things like oil and glue, but still.
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One of my friends remarked the other day that no matter how much space we have, we always seem to run out. He wondered why. At the time, my reply was something along the lines of: "Well, it's for the same reason as your bank-account never has enough money in it."
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While that observation is probably valid, I'd like to point out some side effects of a messy desk.
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If your intent is to operate the radio and get on air to make noise, there needs to be a working station. You need to be able to test it without having to move stuff around and fault finding needs to be part of the way the thing is set-up.
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One station I visited had solved this problem by moving their operating station away from the wall so they had two access points. The front where you operate the station and the back where you test it. That way you get to have your cake and eat it too. The set-up worked really well.
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Picture a few racks with gear, an operating desk arranged in an L-shape, but moved away from the wall, rather than pushed into the corner. Space limitations prevented you from walking all the way around it, but you could get to all but one side of one rack.
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All this was arranged into the space of a standard spare bedroom, pretty much the same as most shack's I've visited. I find myself looking around my own environment with this front-and-rear idea in mind and I'm having a think about how I might apply it.
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Another observation is that we never ever throw anything away, ever. I have seen antenna projects that were doomed to fail from day one, spare screws, bits of wood, drawers and drawers of random electronic components, bits of wire, cut-off connectors, damaged bits of coax, half-wound baluns, empty tubes of silicone, failed micro-switches, bent wave guides, broken windings, arced air-gap capacitors, empty boxes, plastic bags, old radio magazines, all waiting for the day that they become useful, likely never.
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I'm not saying that this cruft is never useful. I'm saying that the chances of them being useful is inversely proportional to the amount. That means, the more junk you have, the less useful it is. Perhaps culling is a way to increase the usefulness of what's left. The ultimate example of something like this is a Go-Cart wheel bearing that I have lying on my desk. It's a piece of precision engineering, but it's stuffed. It has completed it's useful service life, was discarded in the dirt and I picked it up, cleaned it, oiled it and now it sits on my desk. It looks great, feels nice to play with, but as objects go, it's one of the least useful items on my desk, otherwise filled with paper, computer gear and radio gear.
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I just made the bold step to toss it in the bin. Not yet sure how I feel about it, but I'll try by saying that it's the beginning of making the remaining cruft on my desk more useful.
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Perhaps our communal messiness is a thing to do with amateur radio as a hobby, or perhaps we have more than our share of messy members of society. The very nature of our hobby is that we test and trial things whilst doing on-air stuff like making contacts and chatting with friends. Perhaps we should arrange our work-spaces to match.
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If you've found a way to make it work for you, please feel free let me know and perhaps send me a picture or two.
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I'm Onno VK6FLAB
Listen:
Amateur Radio Satellites ... more than two in the sky.
Foundations of Amateur Radio
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There are moments in your life when you say to yourself, duh, why didn't I think of this earlier?
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I had one of those last week.
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As you might recall, I have a hard time using HF communications from my home. There is lots of noise around and I've been going out mobile and portable to make contacts. As satisfying as that is, nothing beats sitting at home in your comfy chair with all the other home amenities.
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Ideally I have this notion that I should be able to do my hobby from home and have my cake and eat it too. Turns out, my duh moment was just that.
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I speak regularly on the local 2m repeater, in fact I host a weekly net called F-troop that encourages new and returning hams to get on air and make some noise in a friendly environment where no question is too silly and mistakes can be made on-air without subsequent yelling and carrying-on.
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So, I have a fully working HF radio at home, but it works just fine on 2m and 70cm.
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My duh moment was when I realised that there are a multitude of 2m and 70cm transmitters around that I could add to my tally of things heard and worked. There are websites dedicated to these transmitters and schedules exist to highlight when, how and where these things are.
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So, what am I talking about?
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The wonderful world of Amateur Radio Satellites.
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There are lots around, sending out idents, having uplink and downlink, sending out digital packets, you name it, the wide variety of Amateur Radio in a 90 minute orbit around the planet.
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I'll confess that I thought there were one or two doing the rounds, but there are a few more. Just counting the active ones, there are 85 satellites designed to be used by Amateurs at the moment, of course that changes all the time, going up and down as more are launched and others stop responding.
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In addition to this collection, there are other things you can listen out for, like weather satellites, the International Space Station and a bunch of other objects.
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I came across the N2YO website which shows you what's up in your sky right now, the foot print and direction, when it clears the horizon, in which direction and what the highest elevation is and when it vanishes again, all very helpful in getting half a chance to hear the transmission in the first place.
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I've said this before, this hobby is magic. I can't do HF, so now I'm playing with satellites. Looks like I'm going to have to sort out some digital decoding software as well, since many of the satellites have all manner of non-Morse code transmissions, APRS, digital modes, graphics, etc. Lots to learn.
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Did I mention that you could do much of this with a hand-held radio? Power is not a problem and an external antenna is likely all you'll need.
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By the way, this is what I like about Amateur Radio, there are so many different aspects to this hobby, so much variety, so many things to learn and experience and I have only just scratched the surface.
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It bears repeating that a beginner's licence in Amateur Radio gives you access to all this and most of the things I've been talking about since I started talking about the hobby back in 2011. I've been licensed now for a little more than a minute and a half, but I still get a pleasant surprise on a regular basis about the size and scope of my chosen hobby.
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There's no excuse, getting bored with Amateur Radio is just not an option.
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I'm Onno VK6FLAB
Listen:
DTMF is something we use regularly ...
Foundations of Amateur Radio
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Ingenuity is the name of the game in Amateur Radio, building, inventing, solving and helping are all part and parcel of this hobby. We like to lay claim to being the source of all that is good in the world, all that was invented came from Amateur Radio first, right?
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Seriously though, sometimes we pick up a technology along the way from other places.
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If you've ever picked up your microphone and pushed one or more buttons on it whilst the push to talk button was down, you've likely used this technology that's set out in an ITU recommendation called Q.23. It has the quaint title of: "Technical Features of Push-Button Telephone Sets". It's a brief document as such, all of four pages, two title pages and one mostly dealing with why this Push-Button idea is a great one and how it relates to international phone calls etc.
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The meat is in the final page, showing eight frequencies and how you combine them to generate voice frequency signals.
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If you've been paying attention, you might recognise this as DTMF or Dual Tone Multiple Frequency signalling.
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It's pretty nifty. Send two discrete frequencies at the same time across some link and decode it at the other end. It's nifty because these frequencies might happen during a normal conversation, but not at the same time for a particular duration.
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As Amateurs we use this to communicate with our repeaters, to send signals to it, to activate links, to power on and off stuff and all manner of other interesting things.
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So, how does it actually work?
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Well, you have two sets of four non-overlapping frequencies which you can combine into 16 different combinations, enough for 10 digits, four letters and two symbols. To make this work, the frequencies must be pretty stable, the ITU recommends less than 1.8% off the nominal frequency and distortion must be 20 dB below the fundamental frequencies.
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Today producing such a thing is trivial, a chip for a dollar will do the job and another one at the other end to decode it. Four bucks and you're good to go for two-way DTMF at both ends. Bargain.
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Being the curios type I went looking to find out what a DTMF circuit might look like before we could buy such products. The closest I came was a build-your-own voice mail system in BYTE! magazine of April 1982 using LM567 tone decoders, but a quick look at the box shows that these are also something that we'd call an Integrated Circuit.
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I'm going out on a limb here, since DTMF has been around since it was first supplied to customers in 1963 and suggest that the original DTMF decoders were not quite as trivial as a dollar chip. They likely contained many discrete components including eight separate filters and ways to combine them so signals could be added to each other to detect the existence or absence of a specific tone, but I've yet to actually lay eyes on anything more fundamental than the tone decoders.
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That being said, you can connect your all-in-one dollar chip, the CM-8870, to something like an Arduino and do your own decoding of DTMF signals.
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Seems that the 1982 BYTE! magazine article was just the beginning of the revitalisation of DTMF, robot controllers, home automation, in-vehicle signalling and more, not to mention, using it to activate IRLP and other wonderful radio services.
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Before you start sending me email about this non-Amateur invention, I'll point out that Amateurs also didn't invent copper wire, that was two Scots, or was it Dutch, I forget, fighting over a coin.
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I'm Onno VK6FLAB
Listen:
The joy of Amateur Radio
Foundations of Amateur Radio
<p>
Last week over dinner I was chatting with a friend about Amateur Radio in a discussion about things that take your fancy. I was attempting to explain what it specifically was about this hobby that keeps me coming back. I talked about invention, about exploration, about fishing and catching that elusive station, but looking back over that discussion it occurred to me that none of that is what "does it" for me.
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Sure, those things are part of it, but it's not what makes me turn on my radio, what has my face light up in delight or allows me to get out of bed in the middle of the night to explore the bands.
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A brief phone call with another Amateur to wish him Happy Birthday twigged me to what's going on. He asked me: "What's new in your world?", and my answer, innocuous at best was: "Well, last weekend I heard a Japanese station from my QTH."
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In the past I've mentioned that I've made many contacts with Japan, looking at my log, 63 of them, on 10m and 15m, so the fact that I heard Japan wasn't particularly special. I don't recall the band on which I heard the station, so that's not it either.
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What was different was that I heard it at home, my QTH. The place where there is S7 or higher noise all the time, where I cannot put up a full antenna and make do with a dipole in the garage and a single band vertical on the roof.
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Looking back at the conversation it occurred to me that what I like about Amateur Radio is the unexpectedness of it, the surprises that come your way, like little gifts waiting to be unpacked. It reminded me of a journey coming back from a club meeting last year when I spent the time going through the entire frequency range of my radio.
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There's quite a bit to visit. The radio in the car does 100 kHz through to 56 MHz as a single range, then has several other ranges. My hand-held is capable of 500 kHz through 999 MHz. Between the two I have the ability to pick up most of the stuff that's around.
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If that's not enough, there are many online radio receivers to connect to using all manner of different tools, the simplest to get running is probably WebSDR, where you visit a web-page and pick out the frequency you want to hear.
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All this RF activity is happening all around us all the time. There's the local Top-40 radio station, the talk back shows, the local community stations, single frequency specialist broadcasters, the local public transit authority, etc. etc. You never know what you're going to find and what you're going to hear.
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Many Amateurs I speak to started off as short-wave listeners. I had a short-wave radio when I was growing up, but it never much did anything for me. Now that I'm an Amateur and I understand what's happening to make those distant signals arrive at my ear, I'm becoming the short-wave listener I never was.
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That's what I like about Amateur Radio. Unexpected gifts being shared across the globe from people, cultures and experiences that bring us all together.
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For me, Amateur Radio is about the thirst for curiosity, the never ending supply of wonder and the joy in hearing them arrive un-announced at my doorstep.
<p>
I'm Onno VK6FLAB
Listen:
Where do you start with this Amateur thing?
Foundations of Amateur Radio
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Being on air and getting on air are part of the journey that you undertake when becoming a Radio Amateur, but what happens before all that, what do you need to get your foot in the door as it were?
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If you're listening to this via a radio, you're already on the journey, but if you've downloaded this as a podcast, you're not far behind and your journey towards becoming a Radio Amateur is just around the corner.
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Let's start with a few things before I start with the journey itself. First of all, every country is slightly different, so while I can give you specific examples, they'll be valid for only a few people.
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In becoming a Radio Amateur you'll have to undertake some learning, pass a test and get a license. This license is specific to you and for most, if not all Amateurs, the license itself is for life. That means that if you have already passed an Amateur License Test in your past, you're likely still a Licensed Amateur today.
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Being a Licensed Amateur, or having a License, doesn't actually mean that you can operate your own station, for that to happen, you need a callsign and the requirements for a callsign are that you have a license. It's like learning to drive. Once you've passed your driving test you're able to drive a car, but you need a current drivers' license to actually get behind the wheel.
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In most cases there are different levels of license. Going back to the car analogy, you can drive a car, a moped or a truck, but not with the same license.
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In Amateur Radio there are several different types of licenses. For example in Australia there are three, in increasing level of responsibility, a Foundation License, a Standard License and an Advanced License. In the United States there are also three, The Technician License, the General License and the Amateur Extra License. In the United Kingdom there are also three, the Foundation License, the Intermediate License and the Full License. Germany has two types and calls them Class E and Class A.
<p>
In essence the idea is that with more learning comes more responsibility and a change of license. To muddy the waters a little, as time passes and Amateur Radio evolves, license types change and merge, new ones are introduced and old ones vanish.
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For example, to my knowledge there are no countries requiring Morse Code as a skill for an Amateur License. That wasn't always the case and until 2003 the World Radio-communication Conference essentially left it to individual countries to decide if Morse Code was a requirement for specific privileges.
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As an aside, Citizen Band or CB, where anyone can walk into a shop, buy a CB radio and use it without passing a test and getting a license is fundamentally different in that the license is linked specifically to the radio itself. There is still a license, and to operate, the license needs to be current, but it's intrinsic to the radio itself.
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Amateur Radio has the license linked to the person, rather than the radio.
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Now that you know a little about the landscape, the next step on your journey towards becoming an Amateur is a little less nebulous. It's probably a good place to start at the beginning and work your way through that and as time goes on and your confidence and experience improves, to add to the learning and do the next thing as it occurs to you.
<p>
I should point out that there are Amateurs who believe that it should be your goal to get the highest level of responsibility, but my perspective on this is quite different. This is a hobby, your hobby. If you want more responsibility, then go do some learning and pass a test. If you're happy to do what you're doing, then do that. Don't let anyone tell you that you must increase your learning, just because they tell you to or that it's the done thing.
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For me, I've set a personal goal to work a hundred countries using 5 Watts and every contact I make counts towards that. If you've been listening for a while you might have noticed that I've not bragged about any remote contacts and that's because I've hardly been out and about on-air using my own callsign. Too many other things to do and I'm in no hurry while I'm learning and having fun.
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So, what's next?
<p>
The simplest is to find yourself a local Amateur and get them to point you to the local training group, but if you're not able to do that, contact your National Amateur Radio Association and ask them who provides training for you.
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You're likely to find a local website with information, or you might listen to the local Amateur Radio News Broadcast where the local training organisation tells you about upcoming courses.
<p>
The first level of license is likely to be pretty simple, think a weekend of listening and playing with radios, followed by a written and practical test. If you have issues with travel or learning, you're likely to find that there are ways to help you get on air, so don't give up, just because you can't drive to the big smoke, don't have a local training organisation or are hopeless at doing tests.
<p>
Amateur Radio takes all types and you too can find a hobby of your liking.
<p>
I'm Onno VK6FLAB
Listen:
What happens if you move the feed point in a dipole?
Foundations of Amateur Radio
<p>
One of the recurring topics in on-air discussion is that of antennas and if we were to graph the topics of conversations, antennas would be the clear winner in any line-up. As a beginning Amateur this phenomenon bamboozled me for a very long time.
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Why are these people talking about antennas all the time and what's there to know that you can't say in 30 seconds?
<p>
From the mouths of babes...
<p>
I've mentioned in the past that Amateur Radio is to a very large degree magic. Another way of expressing that is to say that there is an Art to being an Amateur and antennas play a big part.
<p>
A friend of mine loaned me his antenna kit called a Buddipole. It's a portable set-up that is akin to Meccano or Lego in that you can build up an antenna from parts and make a large range of antennas from the same basic parts, two coils, a feed point, a balun, two telescopic whips and some extension pieces.
<p>
For me this particular antenna has been temperamental and I couldn't get my head around how to make it work. This all changed last weekend when I had a spare 15 minutes, literally, 15 minutes when I went into the shed to have another look. This was spurred on by a note that I'd read that pointed out that the Buddipole is asymmetric, that is, both legs and coils are not the same.
<p>
This important tid-bit of information made things click in my mind and all of a sudden I realised that I didn't need to make both sides the same length, or adjust both sides in the same way.
<p>
Until that moment I'd always thought of the Buddipole as a dipole on a stand and expected like any traditional dipole it would have both legs at the same length.
<p>
What if you could move the feed point along the length of your dipole, what would happen? What if you kept the overall length the same, but by making one end longer and the other end shorter, you in effect were moving the feed point along your dipole?
<p>
Wonderful things start to happen, that's what.
<p>
What I'm saying is that you don't have to make a dipole have equal length legs and that sometimes this is desirable.
<p>
Previously I've mentioned that the height of a dipole, the wire thickness, the ends, the angle and so on all affect the feed point impedance. Turns out, that where you place the feed point also affects this.
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If you recall basic antenna theory, you might recall that the middle of a dipole is the lowest impedance and that the end of a dipole is the highest impedance.
<p>
Each of these values are on a continuum, that is, they vary as you change things. That means that between the two extremes of impedance there are other in-between values. If you have a balun, you can use this to get a great match for your antenna by tweaking these values.
<p>
Another example of this continuum is a loop antenna. If you make it twice as high as wide, the feed point impedance is 50 Ohm, but if you use the same loop and squash it flat, the impedance is 300 Ohm. Varying the shape changes the impedance.
<p>
In essence this means that there is an infinite number of antennas that can be made just as a dipole and another infinite number of antennas that can be made as a loop.
<p>
So, just two antenna types alone already gives you a lifetime supply of options and that's ignoring the height, soil or wire.
<p>
Now you understand why antennas are tricky and why we talk about them so much.
<p>
It also explains why the Internet is full of different explanations on antennas, since they are all based around the local conditions under which the author is describing their adventure.
<p>
Next time you hear an Amateur going on about their antenna, perhaps there's something to take away.
<p>
I know I won't be anywhere as impatient listening to others talking about their contraptions.
<p>
Final thought. A vertical is a dipole too. The radials are one half, the vertical the other. You can change the length of either, or both, but you can also feed the antenna in a different location.
<p>
I'm Onno VK6FLAB
Listen:
DX, common ground on a common term?
Foundations of Amateur Radio
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Have you ever been on air and in the middle of a wonderful discussion that all of a sudden and often unexpectedly erupts into a heated argument about nothing?
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One of those conversations that came to mind was about what the term DX means. I'd been taught that DX means outside the country and if you're calling CQ DX, I was taught that this means that you're looking for a contact in the next country.
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So. What's the argument?
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Simple really.
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In a nutshell, making a contact between Perth and Sydney, nearly 3300 kilometres apart is inside one country, but making a contact across the same distance between say Amsterdam and Lebanon, is about nine countries away. This really means that for every station DX has a different meaning.
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So, this DX caper means different things for different people. I've said in the past that I'd laughed when a station made a big deal about contacting Japan, when that's something I do regularly. The opposite effect happened when I contacted Cuba. For me it's a contact on the other side of the planet, for them it's next door.
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I asked around for explanations from others about what they thought DX meant:
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- Receiving signals & station from remote locations
- Long distance, harder to achieve contacts.
- Doesn't have to be international, all frequency dependant.
- VK[234] to VK6 is DX ;)
- Outside of my suburb !
- Anything hard I suppose, or anything "overseas"
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The take away should be that DX-ing is an activity that means different things to different people. You could put it down to kilometres, or countries, it really doesn't matter. Just be prepared that your measure may not apply to the other station.
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Ironically, thinking back to one of my earlier on-air experiences. I called CQ-DX and got a reply that said something along the lines of "What kind of DX are you expecting?" to which I replied: "Anything I can get." is put into a different context by the knowledge that DX is not a fixed idea. At the time I thought that I had done something wrong and that my activities were some how incorrect. Checking with the amateurs nearby at the time, it transpired that this wasn't the case.
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My insight into the variation of something that looks like a simple concept, DX, puts a different light on the subject.
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I'm highlighting this because I think it's important to understand that when you're on air, you're bringing with you the experiences you have and you're communicating with others who may, or may not share those experiences and understandings, even for something as obvious and common as the concept of DX.
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It also spurs me on to continue to develop my QSL card. If you've sent me one and I've not sent you one back, it's because I'm still very unhappy with the design I've got and I'm working on something that's more me, more Australia and captures the essence of the idiosyncrasy that is me.
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If you're wondering what a QSL card is, think Amateur Radio Postcard. The name derives from something called the Q-Codes, shortcut names used originally in telegraphy, then by Amateurs in Morse, now also heard in all general conversation on air. The code "QSL" means "Can you acknowledge receipt?" when asked as a question, or it means "I am acknowledging receipt." when used as an answer. The card was named after this as a way to confirm contacts between stations. A QSL card generally contains your callsign, their callsign, the time, date, the band or frequency, the mode and signal reports of the contact. Some go overboard with whole novels, include general information about the station, perhaps a picture of your friendly face, or some other image.
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Traditionally, interesting locations, like say Amsterdam Island, activated as FT5ZM go all out in making their cards, since the location is desirable and the card should be as well.
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One final comment. To work DX, you need to be on-air, so get your station in good working order, turn it on and make noise. Making contacts, local and DX is about being lucky and the only way you can do that is by actually being on-air and making your own luck.
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I'm Onno VK6FLAB
Listen:
Propagation is everywhere!
Foundations of Amateur Radio
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Recently I talked about making a propagation map in your mind by listening to the various NCDXF beacons across the globe on various HF bands. You're not limited to listening to a beacon to learn what propagation is like.
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If I tell you that listening to a band gives you an indication on what's going on, you're likely to respond with: "Duh".
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But what if I suggest that instead of listening to a DX station running a pile-up, you instead listen to the stations calling?
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Back in January 2014, episode 133, when this series was still called "What use is an F-call?", I explained what "Listening 10-up" means and how you operate in a so-called split mode. As you might recall, working split is about dealing with the phenomenon that a weak DX station working in some desirable location is likely to be overwhelmed by stronger signals, to the point of no longer being heard. It's a good skill to learn and you should try and work both sides, being the station calling a DX, but also being the one getting swamped.
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As I said, normally you're the one calling the DX station and you don't particularly care about the other stations swamping the band.
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What if you did?
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What if you used their signals to figure out where propagation was happening? If you did that, you could perhaps point your antenna in the correct direction, or specifically focus on calling for stations in that area, or listen out for stations in that region in other parts of the band.
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The thing is, propagation doesn't care what the signal is. As long as you can decode it in what ever way you prefer, Mark I ear-drum, or some fancy decoder, it doesn't matter. If you can hear the signal, it means it's getting from them to you.
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I should note a word of caution here.
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It's taken me several years to realise that I could often hear many stations that had no chance of hearing me. I'd crank up the volume on the radio, listen out for anything and try to work what I heard. Sometimes you get a great result, and you shouldn't discount those, but often all I got for my trouble is a sore head from decoding mush.
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What I learned, especially as a low power operator - I use 5 Watts - if the other station isn't coming in with a reasonable signal strength, S5 or higher, then there's little point.
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There is a concept of reciprocity. The idea is that if you can hear them, you can work them. For some power levels that might actually be true, but for the rest of us, a fine grain of salt should be added to the mix. Before you start in on me telling me I'm wrong, perhaps consider the variations in local environment, antenna differences, not to mention variation in the Ionosphere or alligators, all mouth and no ears running several kilowatts.
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The take-away in all this should be that propagation is everywhere. You can use it to hunt for likely contenders and no signal on the band should be ignored as a potential source of propagation information.
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One final thought. You can also reverse this. Turn on a web based receiver in some desirable part of the world, pick a frequency and then using your radio, call CQ and see if you can hear yourself across the web.
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I'm Onno VK6FLAB
Listen:
The birth and legacy of IRLP.
Foundations of Amateur Radio
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Technology is a moving feast. New ideas spring new inventions which in turn change our lives. Amateur Radio is at the forefront of such inventions. Radio Amateurs have been until recently the only soldering iron brigade around. We've been building things for over a hundred years and we continue as a community to think of new ideas and ways to make them happen.
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For example, we take technologies like AllStar Link, EchoLink, Wires and so on all in our stride. We think nothing of having our radios connected to each other using techniques other than radio spectrum.
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In November 1997, when iPhone still meant Internet Phone, an inquisitive 22 year old amateur called Dave Cameron VE7LTD came up with a way to link a radio to the Internet and the first three Internet Radio Linking Project stations were connected to each other and the now global network of IRLP nodes was born.
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Dave built a DTMF decoder which allowed remote control of a computer and the radio that was attached to it, and made it possible to send the audio from the radio to the sound-card of the computer, which in turn sent that audio in digital format across the Internet to a similarly equipped system where the audio was turned back into a radio transmission.
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This bridging idea took off and many different systems were developed, many of which are in active use today.
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The various systems all use some form of Voice over IP to transmit audio across the Internet, but there are many variations on how the audio gets to the system in the first place.
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In IRLP - as I mentioned - the audio can only come in via an Amateur Radio. EchoLink uses a similar system, but in addition to Amateur Radio as a source, you can register your callsign and use several different applications on your computer or mobile phone to link into the network. AllStar takes this idea further, instead of making a point-to-point connection, the AllStar system is based around an open source telephone exchange called Asterisk and it's used to link together the various systems.
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Other variations also exist. The idea of using Voice over IP techniques spawned a whole set of radio technologies that use similar methodologies to compress voice and then instead of transmitting it across the Internet, use radio waves to send them from one radio to the next. Technologies such as D-Star, System Fusion, MotoBro and DMR built on this idea. Of course these technologies also use the Internet to share information and connect users across the globe.
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There is some contention around these systems. Many Amateurs consider them to be "Not Real Radio", but then I suspect if you look at the birth of SSB, you'll find die-hard CW operators with a similar complaint. The same is true for low power propagation modes like WSPR which aren't real radio because you cannot have a QSO.
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Other issues in the technical sphere also exist. The IRLP software is closed source. You can only buy IRLP hardware from one place and it doesn't allow you to connect in any other way than via a radio. EchoLink now charges for conferences being registered in the system. In the past I've already spoken about Fusion, D-Star and MotoBro and their restrictions around interoperability, licensing and closed source nature.
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From a practical perspective, there are also concerns about the use of these systems in the case of massive failures during local disasters and the like. If the Internet is down, many of these systems will simply become local radio networks. Coverage could perhaps be extended by creating a local mesh network, but HF radio still very much has its place in our world.
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For me this is all about learning and innovation. Ultimately which system you use is up to you.
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I live in a software world where Open Source rules for good reason and my vote will always go to Open Source. To be clear, I'm not adverse to making money, we all have to pay the rent, but making innovation and invention secret is not the way to go in our hyper-connected world.
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I'm Onno VK6FLAB
Listen:
Make your own propagation map!
Foundations of Amateur Radio
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The world is your oyster, but sometimes you need to find a way to test what is going on with your station and determine what is working and what isn't.
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Often I turn my radio on to scanning mode and I set it to scan the Northern California DX Foundation beacons. These beacons, perhaps better known as the NCDXF beacons can be heard across five different HF frequencies, on 20m, 17m, 15m, 12m and 10m. These beacons repeat in a cycle that lasts three minutes, covering 18 different transmitters located in countries scattered around the globe.
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Beacons exist in New York City at the United Nations, in two other locations across the US, in Canada, New Zealand, Australia, Japan, Russia, Hong Kong, Sri Lanka, South Africa, Israel, Finland, Madeira, Argentina, Peru and Venezuela.
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Each beacon rotates through each frequency and then waits three minutes to transmit on the same frequency again. Each transmission contains the station callsign, sent in 22 words per minute Morse code, followed by four one-second beeps.
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The callsign and the first beep is sent using 100 watts, the next one uses 10 watts, the third beep is sent with 1 watt and the final one uses 100 milliwatts.
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What this does is give you a pretty accurate map of what you can hear on what frequency at this time with your station.
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Another way to think of this is as a propagation map that actually uses your station as the receiver. If you can't hear 'm, you can't work 'm.
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If your radio doesn't scan across frequencies very well, there's nothing wrong with listening on one frequency for 3 minutes, switching to the next and so on; 15 minutes later you'll know what propagation is like around your station.
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You can find full details about this whole beacon system on ncdxf.org and I should mention that there are many other beacons around that provide signals for you to listen to.
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As an aside, this system is precisely what prompted me to start the process of learning Morse Code. I'm still at it and you should not take my slow progress as anything other than me being distracted by the other things that are happening in my life.
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If you need something more active and participatory to get a sense of the operation of your station, you should have a listen to the 7130 DX net. It happens every Monday, Wednesday and Friday at 9:30am UTC on 7.130 MHz +/- QRM.
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Next time I'll talk about how that works and what you might gain from having a go.
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I'm Onno VK6FLAB.
Listen:
How to melt coax ...
Foundations of Amateur Radio
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Recently I made a comment about melting your coax and that this was a bad thing. Today I'm going to talk about some of how this comes about and what kinds of parameters we're dealing with.
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Let's start with coax itself. The operating temperature of coax is somewhere around 80 to 90 Degrees Celsius, or 176 to 194 Fahrenheit. Soldering is at 230 Celsius, or 446 Fahrenheit, so for starters, soldering coax is a risky adventure.
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For argument's sake, let's assume that you managed to solder your coax without damaging it. What else can go wrong?
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Let's have a look at high voltage transmission lines. Why do we move power around the place using high voltage lines? The answer is that in a high voltage line, the current is low. Where the current is low, heating is low, so more of the energy gets from the power-station to your shack and less of it is used to heat up the power line between the power station and you.
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So, that means that high voltage and low current is less heat loss. The opposite is also true. Low voltage and high current is more heat loss.
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Now if you look at a dipole antenna, you'll know that this contraption is moving energy around at some or other frequency. As it's doing that, there are high and low voltage points and high and low current points.
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In a half-wave dipole, the high voltage points are at the ends of the antenna, and the high current points are at the feed-point.
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Guess where your coax is?
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So, you've got your connection to your antenna located at a high current point, in the place where high current has the potential to create problems, things like heating up your coax and potentially melting it.
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So, when does this heating happen?
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Well, you need high resistance and high current. This typically happens when you've got a bad connector at the feed-point. In practical terms this means that if you're using QRP, 5 Watts, you're unlikely to come across a situation where this becomes an issue, since the currents aren't that high and a bad connection typically means no contacts.
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If on the other hand you're using high power, then make sure that the connection to your antenna is strong, solid, and water proof so it doesn't deteriorate to the point of melting and then killing your radio.
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It's best to keep an eye on the SWR meter when you're working, since a high SWR might be indicating that the resistance at your antenna changed for the worse.
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Final comment. When you've set-up your station, create a note of the SWR at different frequencies and refer back to that regularly. Spotting a problem early might just prevent some expensive maintenance later on.
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I'm Onno VK6FLAB
Listen:
What is SWR?
Foundations of Amateur Radio
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Today I'm going to talk about SWR or Standing Wave Ratio. As amateurs we use this term all the time, we expect to see it on a meter or display near our transmitter, we buy specific gadgets to measure it and often we seek to find the lowest possible SWR.
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As I've said in the past, the perfect antenna cannot exist, in the same way, a perfect connection, the feed-line, between an antenna and transmitter can also not exist. The perfect match is a 50 Ohm match, but a dummy load is a perfect match and its purpose is specifically not to radiate. So what's all this about then?
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Lets start in a swimming pool for a moment. Imagine that this pool is really long and skinny. Say 100m long and 1cm wide.
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Stand on one side and make a splash. The ripple of the water radiates from the source of the splash, you, to the other end of the pool. The end wall bounces the ripple back to you, and bounces back and forth until all the ripples have dissipated.
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Now, if you kept splashing about, and waves were rippling back and forth while you were splashing, some of the ripples would happen at the same time as a splash and some of the ripples would happen at the time between two splashes. That means that at some times the splash and the reflections would sit on top of each other, making a higher wave and at some times splashes and reflections would be sitting below each other, making the troughs between splashes deeper.
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If you replaced the water with electricity and the pool with a transmission line, the same is true. If you made an electronic splash, say a transmission from your radio, into the feed-line, the ripple would travel along the feed-line, bounce off the end, come back, bounce off the radio and so on. In the same way, reflections and transmissions can add to each other, and they can also subtract from each other.
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This difference between the addition of signals and the subtraction of signals is what we call the SWR.
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There are two ways to get to the SWR. If you connect a 50 Ohm feed-line to a 100 Ohm antenna, the SWR is 2:1. This is a theoretical SWR and it tells you is that there will be a ripple coming back from the antenna that is both adding and subtracting from the original transmission.
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Alternatively we could use an SWR meter to measure the voltage differences between the high and the low part of a wave and indicate on a dial what the SWR is. This is an actual SWR. The two are indicating the same thing and we can use that to get from a measurement to an understanding of impedance matching between the feed-line and the antenna.
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As a point of reference, if there are no ripples bouncing back, then there is no addition or subtraction, and the resulting SWR is 1:1. For completeness, I should point out that the rabbit hole is much deeper than this explanation and I'll revisit this topic in the future.
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Now for the final piece of the puzzle.
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A piece of coax in Amateur Radio is 50 Ohm. If you have an antenna that is 50 Ohm, that's perfectly fine as an antenna system.
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Of course, antennas are not so accommodating. A dipole has a feed-point impedance of about 75 Ohm. A folded dipole has a feed-point impedance of about 300 Ohm. Each different antenna system has a different impedance and thus needs a different transmission line connected to it.
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So, if you look at a 50 Ohm coax connected to a 300 Ohm folded dipole, you know that the SWR is going to be 6:1. However if you connected a 300 Ohm ladder-line to the same folded dipole, the SWR would be 1:1.
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What this means is that the coax would have waves rippling back and forth and the ladder-line would not. The coax would have a particular loss and each ripple going back and forth would be subjected to that loss, where on the ladder-line, the loss would only apply once, on the outbound leg, since no energy would be bouncing back. As an aside, this loss is experienced as heat and if you're not careful it will melt your coax or worse.
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That's not to say that SWR kills everything, but you need to be aware of what's actually going on.
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Now I should point out one more thing.
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These bouncing waves, the ripples coming back have information embedded on them. If you're transmitting voice, or some digital mode, the ripples that bounced back would be broadcast with a slight delay and the second bounce with another slight delay, and so-on. This phenomenon could actually make your signal into gibberish.
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Coax has its place. It's a very flexible way of getting a signal from A to B, it's not affected by crazy nearby signals and it's robust, not to mention cheap. If you actually need to get your signal somewhere, then it will pay to look at how best to use it, when to use ladder-line and how to organise your shack in such a way that the best signal makes it outside to the working end of your radio.
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I'm Onno VK6FLAB
Listen:
What is station security?
Foundations of Amateur Radio
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One of the tick boxes we're required to deal with is the one titled "Station Security". As licensed amateurs we're required to secure our station from use by unauthorised people.
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What form does that take, how do you do it, what makes it secure and how much security is enough?
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I spent a bit of time looking around to see if there were any guidelines I could unearth to actually describe in detail what this might actually mean, but my Google Fu is clearly broken, since I was unable to find any such documentation. That's not to say that it doesn't exist, just that it's well hidden among the hits about encryption, broadcasting music and other spurious results.
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What form does this requirement take in your shack? Do you tick the box and move on, or have you taken specific actions to comply with this requirement?
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For me, I have two shacks. One in my office and one in my car. Taking the car first, the security of my mobile shack is based around the notion that my car is locked when I'm not around. Technically my partner also uses the car and it's not directly under my control at that time, but the flip side of that is that the radio needs to be manually connected to a battery, the head of the radio needs to be connected to the patch lead, the antenna needs to be screwed in and the coax switch needs to match the band you're trying to operate on.
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These things are not complicated for an amateur, but for a member of the public they form several barriers to entry before they could actually operate my station.
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In my office, where I mostly operate on VHF due to the high noise level on HF, security takes a similar form.
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It's in a locked house, that is, if I'm not home, the house is locked. Similarly, when my partner is around they technically can get to the station. The same is true for any guests to our house. Security again is a multi-level activity. The radio needs to be connected to power, the antenna needs to be connected to the correct port, the remote head needs to be connected correctly and if all that is done, you can operate my station.
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There are no specific locks on my radio; the same is true for any station I've ever visited. All of the clubs I'm a member of have a room or a box with a lock on it which is one barrier, but once that is breached, the radio behind it is good to go.
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This whole topic is an example of how we legislate for a particular thing, in this case preventing use by an unauthorised person, but don't actually specify what that means.
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So, what type of security does your station have? What's enough security and what isn't? Is my station legal or not? What makes it so? What about your station?
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It's easy to read the rules and tick the box, but sometimes the tickbox is a deep rabbit hole.
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I'm Onno VK6FLAB
Listen:
Unpredictable radio waves ...
Foundations of Amateur Radio
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Radio Waves travel in straight lines. They go from point to point and that's it. Except that Radio Waves also reflect off certain surfaces, like light does.
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So, Radio Waves travel in straight lines and they also reflect and that's it. Except that Radio Waves also change direction when they pass through some change of medium.
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So, then, Radio Waves travel in straight lines and they also reflect and refract and that's it. Except that Radio Waves also bend when they encounter an obstacle or a slit.
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So, ok that's it. Radio Waves travel in straight lines and they also reflect and refract and diffract and that's the end of it. Except that they turn slightly due to gravity when they pass by a large mass.
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So, this phenomenon that we use in our hobby every time we key up a transmitter or listen to an off-air signal is doing much that is invisible. It bends and wobbles, bounces and shifts, reflects and refracts and somehow we still manage to make our signal get from here to there.
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The reason I'm raising this at all is that all new entrants to the hobby often scratch their head when they start transmitting. Antennas and propagation aside, the humble hand-held portable radio, the walkie talkie, or handitalky, or whatever you call it, does some weird stuff.
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Some people use it like a mobile phone, other talk into it like they're summoning the oracle, others wave it about and hover around metal doorways or hold it close to their body and walk about while they're talking.
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I host a weekly radio net, you should check it out some day, Saturday Morning, 0:00 to 1:00 UTC, it's called F-troop and we get lots of different skill levels and experiences sharing stories and answering questions.
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Many times we have amateurs who are using a hand-held and getting unexpected results.
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This variable, fluid nature of radio waves is why this happens. Each tiny variation causes some effect and some outcome. Resulting in a wildly fluctuating signal that varies between loud and clear and inaudible and all steps in between. And that's not even talking about flat batteries or trying to talk through a hill to a local repeater.
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My point is that radio waves are unpredictable. If you are using your radio in an unpredictable way while using an unpredictable medium like radio, then all bets are off.
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Next time you key up your hand-held, spare a thought for what's happening between your antenna and mine.
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I'm Onno VK6FLAB.
Listen:
Learning from your mistakes ...
Foundations of Amateur Radio
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To do the same thing over and over again and expect a different outcome is the definition of insanity; so how do you avoid making the same mistakes on-air in Amateur Radio?
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During the week I was wading through some old photos and videos on my phone to make some space and I stumbled on some old videos taken by others and sent to me whilst I was on-air. It was a lovely look back at some previous activity, but they also made me cringe. Here's one example, the very first time, back in 2011, I did a local contest, using the club callsign VK6AHR:
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==
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One One. My number to you is uh, one zero four, uh V K Six Alpha Hotel Romeo to V K Six Alpha Romeo, my number to you is one zero four.
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==
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It's only that I know I was using the club callsign that I know who I am and who the other station is, in this case the other station was VK6AR. My exchange was 104, but clear as mud and twice as thick.
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These days I'd say something much less convoluted, something like:
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VK6AR, 59104 from VK6AHR
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Here's another attempt from me in my early days, calling DX using my own callsign:
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==
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"CQ DX, CQ Delta Xray, this is Victor Kilo Six Fox Lima Alpha Bravo calling CQ DX"
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==
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CQ Delta Xray, what was I thinking? Actually, I was emulating another amateur. So what you say, while there are new amateurs in your shack, matters. Also, I noticed that I started the bad habit of saying Fox instead of Foxtrot. Fortunately one of my listeners wrote in to nip that in the bud early on.
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My point in sharing these evolutions of my on-air style is that you might experience me as a practiced amateur, but just like you, I had to learn by making mistakes and being told I was making mistakes. Fortunately there was some video evidence to help in my innocent education stages.
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So, from your perspective, next time you get on air, try and record some of your activity and have a listen back. I've done this with new amateurs and old-hands and it's absolutely staggering how much you learn from having a listen to yourself.
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So, when you get on air to make some noise, record it for education purposes and listen back.
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I'm Onno VK6FLAB
Listen:
Paper Logging tips and tricks ...
Foundations of Amateur Radio
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There was a time when I took my computer out into the field to do my portable logging. That's still true for contests, but when I'm hunting for an elusive DX station, I no longer take with me all the bits that are required to make that level of technology work. I've come to the realisation that less is more. Especially with portable operations in parks and on summits. This move to paper will actually simplify your life whilst you're enjoying the rare stations you can hear.
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So, if you're using paper logs and you are wanting to make actual contacts, how do you do this without going insane?
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Normally you'd find a station, log their call, put down the frequency, scratch it out when the contact failed, rinse and repeat. The end result is a page full of scratched out callsigns with no structure and little chance to accurately log these into your normal station log.
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The best way to overcome this is to take a leaf from N1MM, a brilliant piece of logging software that deserves a whole separate segment and when I'm sufficiently proficient with it, I'll do just that. In the meantime, one of the things you can do with N1MM is mark a station. This mark consists of a callsign and a frequency. Technically it also consists of a mode and a time-stamp, but lets not get too carried away.
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On paper, if you format your log-sheet appropriately, you can use a separate line for each station you hear. Log the frequency while you're writing down the callsign. If you're inclined, you can also write down their name and any other salient details you hear as you're browsing past.
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What this does is set up a framework for you to log your calls. When you actually make contact, then you can enter the signal report and the time. That way you can instantly see which of the lines contain actual contacts and which of them contain stations heard. Sometimes I write down their signal strength as I note the station, but that's a pretty variable thing, so do that in moderation.
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When you've actually completed the contact, make a mark, either an exclamation point or two, or an asterisk, or something that you recognise. That way when you're sitting in front of your station log, you can quickly log those specially marked contacts and add them to your DXCC tally.
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This same technique works well during search and pounce operation during a contest, though I personally am unlikely to use paper for contest logging; N1MM is very helpful in keeping track for you. As a bonus, N1MM allows a station to expire, so your screen isn't filled with stations that are no longer there.
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I should point out that I'm making the assumption that you're the one responding to another station, rather than sitting on a frequency calling CQ. If you're doing that, just log their callsign as they come past, keep track of the time and write down any signal reports when they're happening. That way you don't get ahead of yourself and you'll end up with a log that still makes sense later on.
<p>
Logging is important for your own benefit. Some jurisdictions require a station log, for others it's optional. If you're interacting with other stations, logging their call is a courteous thing to do.
<p>
I'm Onno VK6FLAB
Listen:
The FM Capture Effect and other Amateur Radio magic...
Foundations of Amateur Radio
<p>
Today I'm going to talk about magic. In the past I've made mention of the magic that is Amateur Radio. There are those who think that our hobby isn't magic and that everything that we do in this field is understood and documented.
<p>
I think that this is both wrong and unhelpful, since there is much to learn, much to discover and much to invent. Amateur Radio isn't dead, it's full of life, full of things that are continuing to develop, evolve and grow.
<p>
Let me give you an example.
<p>
In radio there is a phenomenon called the "FM Capture Effect". Explaining how you experience it is simple. If you have two FM transmitters on the same frequency, and you're using an FM receiver, one of the FM transmitters will win, that is, you'll hear one and not the other. Unlike in AM and SSB transmissions, where you hear both at the same time, the FM Capture Effect causes the receiver to pick one over the other.
<p>
As an aside, it's because of this effect that aviation and HF communication mostly prefer AM based communication. Imagine two pilots trying to talk to the tower at the same time, one is heard and the other not.
<p>
Back to the magic. We can describe that this thing happens. We can show it happening, we can even measure the signal strength difference that causes it to happen, 0.17dB according to one document I read. We can use formulas to describe our FM signal, we can use simulations to emulate it, but in the end, the closest we can get to the how and why is: This happens, we know it happens, it happens under these circumstances, but precisely how, we're not sure.
<p>
A thesis I read on the subject by Park Soon Sang at the Naval Postgraduate School in Monterey, California, published in 1989, spends many pages saying all these things and finishes off with: "The simulation results establish that the low pass filtering portion of frequency demodulation accounts for the capture effect of FM receivers." and goes on to say: "It is recommended that the capture effect be verified using an operating experimental system in which system parameters can be controlled and accurately measured."
<p>
Or in other words, we built a software simulator to learn about this phenomenon. This simulator suggests that the low pass filter causes this, but you really should make an actual set-up to test this.
<p>
If I'm less vague, we simulated it, it looks right, but we're really only guessing, so test this in the real world.
<p>
Now, before you get all huffy. I'm saying that a phenomenon that has existed since the first FM transmission in 1936 is still being explored and investigated and the jury is still out as to what precisely causes it and what the parameters are.
<p>
As Arthur C. Clarke wrote in 1973: "Any sufficiently advanced technology is indistinguishable from magic." -- by that definition, Amateur Radio is clearly magic.
<p>
So, when you next scratch your head about what the future of our hobby has in store, the answer is almost certainly covered by the very same author: "The only way of discovering the limits of the possible is to venture a little way past them into the impossible."
<p>
Amateur Radio, it's magic and there is more to discover.
<p>
I'm Onno VK6FLAB
Listen:
Don't ever yell into a microphone and other neat things ...
Foundations of Amateur Radio
<p>
This technology driven community of radio enthusiasts makes me laugh on occasion. Today I had to laugh when I realised that we spend an awful lot of time talking about antennas and radios and feed lines and impedance and propagation and electronics and a whole lot of subject in-between and around that.
<p>
It stuck me that one conversation that we don't have, is the one about microphones. Specifically how to actually use one. I've been around hundreds of radio amateurs, seen them speak into their microphone, witnessed them standing at a lectern presenting their latest project, observed them attempting to rally the troops during a HAMfest by yelling into a microphone and heard them on-air.
<p>
I came to the realisation that despite our familiarity with the technology, by enlarge, the amateurs I observed are no better than the general public when it comes to using a microphone. Actually, I think as a community we're worse, because we won't be told how to do it.
<p>
So, I'm going to tell you. You can switch me off, or in the secrecy of your own shack, stick around and see if there is something to learn.
<p>
I'm coming at this from a background in broadcasting. I've conducted some 1800 interviews in my time, have spoken in public, on-air and in myriad different environments, including large event venues and sports arenas. I won't say I've seen it all, but I've seen my fair share of how it's done, what it sounds like and what doesn't work.
<p>
The very first thing to note is that yelling into a microphone will make it worse. Let me say that again. Don't ever yell into a microphone.
<p>
The second thing to note is that you should keep the distance between your mouth and your microphone as static as possible. A good rule of thumb is to clench your fist and put it between your chin and the microphone. That's the distance that you should start with. Some microphones need you closer, others need you further away. Eating your microphone is only for very experienced operators in specific environments, since every thing your mouth does will be captured.
<p>
A microphone is in essence a device that converts movement into electricity. This sounds obvious, but it means that waving the microphone around is also movement. The cable that's attached to the microphone moves, and makes sound. The desk on which the microphone is placed moves when you touch it, that's sound. Anything you can hear with your ears and much that you cannot, will be captured by the microphone.
<p>
Not all microphones are equal. The ideal microphone converts all frequencies equally well, but this isn't actually possible, so, some frequencies are better captured than other frequencies. This means that your voice will not actually be captured in exactly the same way as it comes out of your mouth.
<p>
Speaking of which. What you hear from a recording of your voice often sounds wrong. This is because the sound that's coming from inside your mouth is also travelling inside your head and your ears pick it up from the inside as well as from the outside. Listening to a recording of your voice doesn't echo inside your head.
<p>
On an FM repeater, if your signal is captured by the repeater, the volume is not due to your antenna, it's due to your microphone. So make sure you set the microphone gain appropriately and when people tell you that you sound soft, fix the gain.
<p>
Microphones will pick up breathing and the sounds your lips make when you smack them together and when you say the letter P as in PaPa.
<p>
The best way to deal with this sound is to learn not to make it. In the mean time, you can speak across the microphone, rather than directly at it. This means that you should keep the same distance, but tilt the microphone slightly.
<p>
Speaking into a lectern microphone, a radio microphone or a hand-held all follow exactly the same principles.
<p>
If you get the opportunity to hear yourself via headphones while speaking into a microphone, use it to listen to what exactly is captured. You'll get distracted by how your voice sounds, but have a listen to the smacking and the breathing and the popping of your voice.
<p>
Final tip. If your voice gets tired from speaking and you run out of breath, you're doing it wrong. Touch your belly while talking, don't press down, just touch it. You're aiming to use your whole body, feeling your gut participate in the speaking. Technically what you're doing is making your diaphragm move, but that's hard to imagine. Touching your belly does the trick.
<p>
No more excuses. When you get on air, make sure that the beginning of the link between you and the other station is fully functional, start with getting the microphone right.
<p>
I'm Onno VK6FLAB
Listen:
The band is dead and there are no contacts to be made...
Foundations of Amateur Radio
<p>
There is a curious phenomenon related to how we operate that is pervasive within our community. As an inexperienced ham, I would turn on my radio and tune around and hear nothing. I'd change bands and do it again. Over time I'd work my way through the bands I'm allowed on and find no activity.
<p>
On rare occasions I'd venture into the wide unknown and see what other bands were doing, ones where I wasn't allowed to transmit due to my license restrictions, and find lots of people talking to each other, making noise and having fun. More often than not, this band of feverish activity was 20m.
<p>
For a long time I ascribed magical properties to this 20m band. There was always propagation, people were always there and it seemed that if you wanted to make contacts, that was the place to be.
<p>
Over time I participated in contests with other amateurs, operating a club station and finding myself on 20m making contacts. I began to believe that 20m was this amazing place where stuff was always happening. This seemed to be reinforced by other amateurs who would use as their sole reason for gaining extra responsibilities, access to the 20m band.
<p>
Now before you start, 20m is special. It has some interesting properties which make contacts appear and vanish at short notice. Just like other bands with their different peculiarities, practice makes perfect.
<p>
But, 20m isn't that special. It's not a band that is always open, or always closed, just like 15m isn't, nor is 10m, neither is 6m, 80m, or 160m or whatever band you prefer to operate on. No band is always open and no band is always closed.
<p>
Guess how I know this?
<p>
Whenever there is a contest, activity blooms all over the place, the bands are full of stations, making contacts, having fun and annoying those stations who hate contesters with vehemence, so, clearly there is something else going on.
<p>
There is.
<p>
It's you, and me, and everyone else. We're all listening. While listening is good, you also need people to talk, otherwise there is nothing to listen to. There are automated stations around using beacons and WSPR modes and all manner of cute software to determine if their station is being heard. And if you look at the maps, they clearly are being heard.
<p>
So, as I've said before, go on air and make some noise.
<p>
If you want to make contacts, you need to make noise. Your friends need to make noise. You need to setup regular contacts with friends somewhere on the planet and actually use the bands.
<p>
Yes, having access to 20m is fun, but lamenting that is frankly a waste of time. Whatever band you're on, whatever you're doing, you need to make noise.
<p>
Yes, of course there are variations in propagation throughout the day and the solar cycle affects how far and wide you'll be heard, and sun spots and solar flares affect the ionosphere as well, but it's not the only variable.
<p>
Just because no-one is heard, doesn't mean that no-one is there.
<p>
So, repeating myself, go on air and make some noise.
<p>
I'm Onno VK6FLAB
Listen:
How old is the mode you're using?
Foundations of Amateur Radio
<p>
The thing I like about our community is that there is always something new brewing, someone is inventing something, making something or doing something. It amazes me that the level of ingenuity is boundless.
<p>
During the week someone asked the question, "What's the difference between AM and FM?" and while answering that could incorporate hand waving, arrows and drawings, I came across a much simpler explanation, which simply says it all. Credit goes to redditor EmmetOT.
<p>
Imagine replacing radio with light, this isn't a stretch, since it's part of the same spectrum. Replace a radio transmitter with a light bulb. AM is using a dimmer, changing the brightness, to send information. FM is changing the colour of the light to send information.
<p>
I could stop right there, but there is so much more going on in our community. If you've been out of Amateur Radio for a while, and I know, this happens to the best of us, you'll be forgiven in thinking that nothing is the same as it was, while wondering if anything ever changes. Both these things are true and I think that's good.
<p>
The first AM voice transmission was made in 1900, SSB experimentation began in 1915 and FM experiments were happening in the early 1930's.
<p>
These three modes, AM, SSB and FM are still with us today. We've done other cool stuff since then, stereophonic and quadraphonic FM. We think of RTTY as a relative new kid on the block, but it has its origins in 1874 and the first on-air RTTY was heard in 1922.
<p>
Without going into too much detail, other modes that we are beginning to think of as ancient are surprisingly new. PSK31 for example joined us in 1998, but Hellschreiber, is from the 1920's, MFSK comes from 1962 and Packet Radio hails from the 1970's. JT65 comes from 2003 and JT9 is from 2012.
<p>
My point is that whatever the mode you're using, someone is extending it, modifying it, improving it or inventing something new. Your level of familiarity with a mode has little or nothing to do with the age of the mode.
<p>
As is the case with everything in Amateur Radio, horses for courses.
<p>
In your Amateur pursuits you'll come across those who will tell you that there is nothing new to be invented, that everything has already been thought of and that we are a hobby of old people harking back to the golden era of something or other.
<p>
I'm here to tell you that nothing is further from the truth.
<p>
Amateur Radio is a hobby of invention of people asking the question: "I wonder what happens if I do this...", often followed by a big bang and the magic smoke coming out. Don't let that deter you. Keep on with the experimentation, even if you've only been a member of this community for a minute and a half like me, you too can make a contribution.
<p>
I'm Onno VK6FLAB
Listen:
Alternating Current and Direct Current are the same thing ...
Foundations of Amateur Radio
<p>
When you use your trusty multi-meter to measure resistance across a 50 Ohm resistor, it shows 50 Ohm, but when you use it across a piece of 50 Ohm coax, you see either infinity, or 0. Similarly, when you measure across a folded-dipole, you see 0, not 300 Ohm. Does this mean that a 50 Ohm resistor is somehow different than a 50 Ohm piece of coax and why is the feed-point impedance of a folded dipole 300 Ohm, when your multi-meter clearly says it's 0? Does this mean that there are two types of Ohm? Today I'm going to explain why this is and what's going on.
<p>
Yesterday I started reading up on the subject and every single explanation I came across went into deep ju-ju with scary maths, using complex and imaginary numbers. I did a bit of that in my dark past, but none of that is needed to understand what's happening.
<p>
As you know, there is such a thing as Direct Current or DC - we use it with batteries and little power supplies, in simple circuits and all manner of day-to-day activities. There is another world that we as amateurs use, the world of Alternating Current or AC. In house-hold wiring we use 50 or 60 Hertz and different voltages depending on where on the globe we are. In radio terms we use it for our transmissions, on HF at several Mega Hertz and beyond.
<p>
These two different worlds, the DC and AC world don't appear to have anything in common.
<p>
Here's the kicker though, they are the same thing. Yup. DC and AC are the same thing.
<p>
What?
<p>
Yup. I'm not making this up.
<p>
As you might recall, if you look at an AC voltage, it goes from plus to minus and back again. A 50 Hertz alternating current does this swap 50 times per second. When you're rag-chewing on 40m, or 7 MHz, it happens 7 million times a second. From plus to minus and back, 7 million times. Clearly there has to be some impact on this massive level of activity.
<p>
Think of direct current as an alternating current with a frequency of 0 Hertz, that is, over time, DC doesn't change. So, DC is a short cut for saying AC at 0 Hertz.
<p>
If you understand that explanation, then some really cool stuff starts to happen.
<p>
Before I get to the cool stuff, you might recall Ohm's Law, commonly expressed as: "Given a current and a resistance, we can determine a voltage". Said in another way, the resistance of a circuit is related to the voltage and the current in the circuit.
<p>
Now, in this simple form of Ohm's Law, the voltage doesn't change from plus to minus and back again. That is, over time, there is no change. Now if you start doing funky stuff with your voltage, like change it from plus to minus and back again, an additional type of resistance comes into play, called reactance. This reactance is the part that is affected by voltage change over time. So if you swap the voltage from plus to minus and back again a million times a second, the reactance has a big part to play.
<p>
In short, there are two types of resistance, one that is independent of time, called resistance, and one that's dependent on time, called reactance. Both of these, resistance and reactance, happen within a circuit. If the voltage doesn't change over time, then the reactance part is zero and similarly there are circumstances where you can have a resistance of zero but have a reactance that's not - one example is a folded dipole.
<p>
Now, if you combine the resistance and reactance, you get something called impedance. Now you have all the bits.
<p>
Resistance is expressed in Ohm, Impedance is expressed in Ohm, and thus Reactance is also expressed in Ohm.
<p>
If we look at our folded dipole with a feed-point impedance of 300 Ohm, you now know that this 300 Ohm comes from a resistance of 0 Ohm and a reactance of 300 Ohm at the resonant frequency, which is why your trusty multi-meter shows it as 0, since the voltage it uses to measure is alternating at 0 Hertz, which is not the resonant frequency of this antenna.
<p>
Before I go, the rabbit hole goes deeper. Reactance itself is made up of Capacitance and Inductance, which each deal with the reactance in a capacitor and an inductor, but I'll leave that for another day.
<p>
So, next time someone tells you that the feed-point impedance of your folded dipole is 300 Ohm, you'll now understand why your multi-meter says it's 0.
<p>
I'm Onno VK6FLAB.
Listen:
After the contest ... the debrief.
Foundations of Amateur Radio
<p>
Today I'm concluding my breakdown of the contest that I participated in recently as a mobile station.
<p>
I planned to make my contacts on one band and I did that. Feedback indicated that there were other contacts to be had on other bands, but switching bands is a non trivial affair with my current set-up.
<p>
I planned to have a common frequency that would be a local cluster of activity, except it never happened that way because others decided to do their own thing. This meant that my antenna was tuned for the top end of the band, rather than the more typical centre of activity.
<p>
I expected to work several home stations and managed to do so with two, but that was much lower than I expected and planned for, so my overall score didn't reach the planned levels, even if it was triple last year's effort.
<p>
I planned to drive a circuit in about 90 minutes, instead it took about three hours. Fortunately there were lots of mobile stations about which helped me much more than expected.
<p>
I keep telling myself that I need to sort out a voice-keyer because each time my voice gives out about half way through the contest, but again I keep forgetting to make that happen.
<p>
My laptop power worked pretty well, but the location of the device, sitting on the passenger seat and then during on air activity, parked at the side of the road, it was balanced on my knee. Not ideal and not comfortable.
<p>
My phone worked really well as my live GPS map and the boundaries I'd drawn using Google My Maps really helped to show me where I was in relation to the boundaries for this contest.
<p>
I'm a relatively new arrival into the Amateur community but I often forget that I've been contesting almost from day one. My first on air experience was a club station during a field day camp out where the activity centred around a little folding table with Amateurs crowded around it. On air I have lots of broadcast experience, which means that I'm experienced in multi-tasking, coordinating frequencies, logs, callsigns, navigation and strategic objectives. I forget that this is not true for others on air.
<p>
I love contesting, seriously, I love it. This activity puts me right on the bleeding edge of my capability and it's exhilarating to explore the peaks and troughs of the activity.
<p>
I used rope to prevent my heavy antenna from breaking my boot lip mount and was worried about strange looks I might get. The rope worked well, the mount did not suffer from the experience and I didn't get much in the way of strange looks. In fact, much less than when I'm parked up with my 12m squid pole.
<p>
Food and water worked great, but I will add public toilets to my map for next year, since it's not fun having to hunt. Mind you, a petrol station is a good option when you're in a hurry.
<p>
At the end of the day, I managed to triple my score, I achieved all my objectives and proved to myself that my strategy, which came about thanks to discussion with fellow contesters, was solid, workable and a better performer than last year.
<p>
I'm not yet sure how I'll change what I did, perhaps more antennas, parked at places longer, working more bands at the time might be an improvement. Time will tell.
<p>
I hope that this adventure made you look at your activities and gives you some ideas on what to try, what to investigate and things to look out for.
<p>
Hopefully I'll hear you on air during the next contest.
<p>
I'm Onno VK6FLAB
Listen:
How to make contacts during a contest?
Foundations of Amateur Radio
<p>
Today I'm going to look at the actual on-air activity of the contest. Previously I've talked about the preparation and planning, as well as the doing, in terms of mechanics, what to bring, where to put it and how to power it all.
<p>
At the most basic level, a contest is a combination of two things, making and taking calls. It's an important point, so I'll say it again. A contest is two things, sitting on a frequency and call CQ and have other stations call you, and, it's also hunting up and down the dial finding other stations who are calling CQ.
<p>
These two sides, being the instigator of the contact, and being the responder, are needed to make points. Even the most advanced contest station with multiple operators and transmitters will do both these things and when you're on your own you too need to do this.
<p>
One reason for this is that in a contest others are doing the exact same thing. They're also swapping between both these activities to pick up extra points and multipliers.
<p>
Another reason is propagation. Your station is unique. It has a unique radiation pattern, a unique location, a unique audience of stations that can hear you at any one time. Across the duration of the contest this will change as day turns into night and night back into day. If you're mobile, there is an additional variable, your location which will affect your audience every time you move.
<p>
If those two reasons were not enough, here's one more. How do you know if the band your on is working or not? How do you know if there are others nearby, or on a completely different part of the band, or, if the band is open or closed, or if solar conditions have shifted and a band has been affected?
<p>
For my contest I had a vertical antenna mounted on my car. I can use it to operate on the bands I'm allowed to use, 10m, 15m, 40m and 80m. For this contest, my go-to band was 40m. Local conditions dictate that when dusk arrives, the lower part, 7.0 to 7.150 is all but unusable due to heavy interference from non-amateur stations overseas, so I picked a spot near 7.190 and used that as my calling frequency.
<p>
Of course, as was expected, not everyone got the memo that I'd be up at that end of the band, and the little flag I posted saying that this was my frequency was dutifully ignored by everyone.
<p>
What I'm saying is that there is no such thing as "my calling frequency", just the place where you like to call and you have to manage this along the duration of the contest, since others will find your little hidey-hole and use it at the drop of a hat. And if you're QRP like me, they might even just start calling CQ right over the top of you and you'll find that you think you're making contacts with stations that are not actually talking to you. In other words, be flexible.
<p>
As a rule, for myself, having been bitten by this many times, I don't QSY to another band if a station I've just worked asks to do so, since the aim for your contest is for you to make contacts, not for someone else to make them. That's not to say that if it's 3 o'clock in the morning and nothing much is happening this won't change. Again, flexibility is key.
<p>
I tend to use both VFO A and VFO B on my radio. It's a quick way to swap between frequencies or bands and it allows you to both sit on a frequency, calling CQ and hunt up and down the band at the same time. If that doesn't make sense to you, this is how I do this.
<p>
I set my calling frequency up on VFO A and copy that to VFO B. I call CQ a few times on VFO A, swap to VFO B, scan up or down a little way, find a station that I'd like to work and swap back to VFO A, call CQ a few more times, swap back to VFO B, hear the station finish their call and hear them call CQ. I respond and if they hear me, I make the contact. If not, I swap back to VFO A, call CQ and do it all again. This way I can be in one place calling CQ and pick up contacts at the same time.
<p>
If you have multiple radios, even as a single operator, you can do this and pipe the audio from one radio into one ear and the audio from the other radio into the other ear and do both at the same time. You can even combine the two and have four frequencies you work on. This requires practice, and you must make sure that both radios are not on the same band, ever, otherwise you'll likely blow up the second one while transmitting on the first.
<p>
Next time I'll look at what worked and what didn't, the aftermath.
<p>
I'm Onno VK6FLAB
Listen:
The logistics of being in a contest while mobile
Foundations of Amateur Radio
<p>
Today I'm going to talk about the doing of a contest. Previously I discussed the preparation and you can go back to that and have a listen online, search iTunes for my callsign, VK6FLAB.
<p>
The contest I participated in was a 24 hour contest. It started at 2pm local time on a Saturday and ran the whole 24 hours. If I was sitting in a shack, I might have and in the past actually have, operated during most of that.
<p>
Seeing that this time around I was planning to be mobile, I needed to get sleep in between driving from location to location.
<p>
In my car I have a suction cup stuck to the front windscreen which holds the head of my radio. It's mostly within reach, but if I operate for a little while, extending my arm gets tiring, so if that's the case, I drop the steering wheel, push it forward and modify my seat position.
<p>
A better solution would be to find a better location, but I've not managed that yet. I keep looking at other set-ups, but haven't found one that works for me. I'll let you know if I do.
<p>
My logging is done on a computer. A net-book. It's small, light and pretty responsive. It's running Windows XP, never connects to the 'net and it works. I balance it on my knee when entering contacts, or have it on the passenger seat and tap into it that way. Also not ideal.
<p>
I saw a series of photos where a fellow traveller had used a plastic sewer pipe, and bend, to push into the cup-holder of the centre console and mount their computer on that. I've not yet travelled to the hardware store, but I can see a future where that might occur.
<p>
Power for the laptop comes from a 12V power supply. It's plugged into the cigarette lighter, set to the voltage of my computer and plugged in. It has a handy USB socket on the power supply that I use to keep my phone charged. That sits on another suction cup on the dashboard in a mount. It showed me where I was and where the boundaries of operation where. Every now and then I even used it as a phone.
<p>
Speaking about power. I power my radio with a 12V battery that's sitting in the boot.
<p>
At night, finding the right keys to press is a challenge. The interior light of the car is one option, but I find it makes too much light, draws too much attention and uses more power than I'm willing to use. Instead I use an LED headlamp. I was wearing it for a while, but a better solution turned out to be attaching it to the sun visor where it still is.
<p>
In terms of feeding and watering, for water I had about six bottles of water lying in the passenger seat foot-well. For food, a small insulated bag with fruit, apples, pears and a banana. I stayed away from nuts, sugar and other traditional stay-awake foods, because I find that I over eat, get sleepy and become less productive.
<p>
In between locations I'd turn the radio volume down, turn on some classical music and let my mind relax a little.
<p>
I drove about 300km during the 24 hours. Operated from 2pm until about 10pm and from about 5am to 2pm, a total of 17 hours. I managed to have a sausage roll for breakfast, not recommended, a few cups of coffee in the morning - keeping my eyes peeled for a coffee place at 5am paid off at 7am.
<p>
I wore comfortable shoes, a t-shirt and jeans. Next time I'll wear shorts or tracksuit pants. The belt really didn't work for me for that extended period of time sitting in a car.
<p>
Next time I'll talk about the operation during the contest.
<p>
I'm Onno VK6FLAB
Listen:
Training, Traumatic or Fun, you decide...
Foundations of Amateur Radio
<p>
Training is a word that is steeped in tradition, it conjures up images of classrooms, teachers, chewing gum stuck to the bottom of your desk and being called upon to attend the front of the class to explain something based on the misapprehension that you did your homework.
<p>
Fortunately this is a hobby and training is something you can do yourself, to yourself, by yourself at your own pace. Of course, you can choose to do it with others, but it's not required as such.
<p>
We talk about being prepared for doing stuff, but what do we actually do to make that happen?
<p>
I've said many times that I like to do contests. In fact, I'm preparing for one right now. This particular contest awards points for making a contact and doubles the points, a so-called multiplier, every time I work a different area.
<p>
So, what does my training for this look like, what preparation have I done and what am I doing right now?
<p>
My first step was to read the rules, the specifics of what is proscribed, what is permitted and what is counted and what isn't. This sets up the training ground, the framework under which I have to operate my station.
<p>
My next step was to pull out a map and draw the boundaries of the areas that affected my score, showing those regions that I'd likely be in and likely make contact with. The crucial part for this was to see where the boundaries were, because it's likely that while driving around, having situational awareness will pay a good part of being successful.
<p>
Then I looked at the band conditions. I set-up with my multi-band antenna, a multi-tap Outbacker, and set it up on the 4 HF bands that I'm allowed to operate on, 80m, 40m, 15m and 10m. I set out to make a single contact with each, based on another station a couple of kilometres up the road. We both have vertical antennas to increase our chance of success.
<p>
Based on that I determined a few things. One, that this particular antenna and my car make for some pretty specific directionality on some bands. Two, that 10m and 15m were working close in, but not 20km away, that 80m sort of worked but that 40m was a winner.
<p>
Based on this test I decided that 40m was going to be my frequency band for this contest.
<p>
Then I went about getting tools together. I have a laptop for scoring and a power supply that connects to the car for the laptop. I've charged my radio battery, so it will run for a week on 5 Watts, got together pen and paper as a backup, found a USB charger for my phone and will shortly be packing fruit and water for while I'm on the road.
<p>
Last night I fuelled up the car, ready for the contest, and this morning I dug out a few spare antennas in case one of my friends is able to come out and play on-air as well.
<p>
I've looked at the map closely, did maths on how best to operate, added markers to my map where good operating positions might be found, likely they're completely rubbish, but going there is when I'll find that out.
<p>
I've told others what I'm going to do, encouraged others to get on air and play and by the time I start I'll have had a healthy lunch, a hot shower and comfortable clothes to keep me on the road. I've packed a warm coat, and gone through the contest in my mind to see if I can think of other things that I might need.
<p>
All this is only the pre-cursor to actually doing the contest. Call it Part 1. Part 2 is the contest and Part 3 is figuring out what worked and what didn't. I'll tell you about that next time we meet.
<p>
Training, it can be fun, or it can be traumatic, you decide.
<p>
I'm Onno VK6FLAB
Listen:
How to get started ...
Foundations of Amateur Radio
<p>
Today I'm going to talk about getting started. In the past I've mentioned that it's a good idea to find a community, a club or a local mentor to get you going in this hobby, and that still stands. You really need to find some like-minded, available humans to share this experience with. That being said, there are some things that you can do on your lonesome.
<p>
An often asked question is: "What radio should I buy?" The answer to that question can be long and involved, but it boils down to this: "What ever you can afford."
<p>
That answer in and of itself isn't that helpful. Do you get a $40 cheap hand-held or a $4000 all-singing and dancing radio?
<p>
My best answer to that is: "Buy your second radio first." What I mean is that if you spend your money on a $40 radio today, how long will you enjoy it and how long will it be until you spend your next bit of money and is that $40 investment a waste of money?
<p>
I'm not making a value judgement here, the answer is still: "What ever you can afford."
<p>
When I asked that question of my mentor, Hi Meg, she explained that her first radio was a hand-held radio and that she quickly settled on a Yaesu FT857d as her second radio. She went on to say that picking a brand is like choosing between Mac or PC, Ford vs. General Motors, vi vs. emacs, Debian vs. Red Hat, Tomato vs. Tomato. There are followers in each camp and nay-sayers in every other camp.
<p>
I picked my radio based on whom I had around me for support, who was nearby for silly questions, advice on accessories, experience with settings and knowledge of costs, faults and other intangibles that I was completely unfamiliar with.
<p>
Once you get into this hobby, you'll come across people who have technical reasons for picking a particular radio, or sentimental reasons, or financial ones, or what ever reason they come up with. When you get started, not much of that matters. If you have money to burn, then sure, you can by the top-of-the range radio, but if you're never going to use it, what's the point?
<p>
Once you've picked your radio, other choices follow. What power supply do I need, how much space do I need, what kinds of connectors does it come with, has it got a built-in antenna, or do you need to erect one, does it have a tuner built-in, or do you need to get one, do you need programming software, a microphone, etc. etc. Each of these follows from the initial selection of your radio.
<p>
What now? You have a radio, presumably an antenna of some sort and your radio is actually turned on and you can hear stuff.
<p>
If you've come from a short-wave listening background, you'll know where everything is, have a familiarity with the bands and an idea of how things work. If you're new to this hobby, then these things are not so obvious. Things to mention are that each band is unique, that is, they all have their own characteristics. Some are always noisy, others are always quiet, some are active during the day, others only at night, some have stations all day long and others only for short periods.
<p>
A lot of this depends on things outside your control. Propagation is a variable animal and depending on what our Sun is doing, propagation will change, sometimes substantially, as time goes by. Forecasts for the weather are getting better. The same is true for propagation forecasts. A forecast is just that, a prediction of the environment, but not a guarantee of conditions.
<p>
There is no substitute for turning on your radio and having a listen. If you're in someone else's shack, have a listen on their equipment, use the opportunity to learn something about different set-ups. If you get the chance, operate on that station and see what happens.
<p>
Getting started isn't a magical invisible unattainable thing, it's taking the first step on your journey into this hobby of Amateur Radio.
<p>
Get to it already.
<p>
I'm Onno VK6FLAB
Listen:
A surprise might be just around the corner...
Foundations of Amateur Radio
<p>
This crazy hobby keeps sending curve balls to me. You've heard me talk in the past about missed opportunities. There are times when you look back and ask yourself: "What was I thinking?"
<p>
Over the past, oh boy, I just looked it up, two years, I have been struggling with an antenna system that I could use while mobile. I took delivery of 4 single band antennas, one for 80m, one for 40m, 15m and one for 10m. I also purchased a boot-lip mount and some other things like coax switches and adapters.
<p>
I've been attempting to make these antennas work with very, very limited success. They work just fine, they tune up as expected, show the SWR curve that the manufacturer has helpfully printed on a little card that comes with each antenna and generally are sturdy, compact and wonderful, but only if they're installed on something other than my car.
<p>
In desperation a year ago I purchased a tuner for my radio, so at least I can trick it into transmitting. I have made very few contacts, added one or two DX countries in the past year and really got no-where.
<p>
So, during the week I recalled that one of the things I purchased was an adapter. It's got a PL-259 socket on one end and a CB-thread on the other. I dug it out, found the thread that goes into the hole and attempted to attach it to the CB antenna I was given within a month of becoming an Amateur. It had been modified to work on 10m and most of my DX contacts had been with that antenna.
<p>
So, I attempted to attach the adapter and it doesn't fit.
<p>
So I look around my shed and notice another antenna that I was given at the same time that never worked, it's a multi-tap antenna. Picture an antenna that is a big stick, has wire would around its entire length with points where you can attach a lead to bypass some of the antenna. You plug the lead into the bottom connector, then pick the band you want to work on, put the other end of the lead into the right tapping point and off you go. It came with a big spring mount, was intended to be bolted to a bull-bar, but using a family sedan, makes attaching this contraption pretty hopeless. It'd tested it where I could, measured it, tested more, made a new wander lead with a solid connector and nothing I did made it work.
<p>
It turns out that the thread in my adapter fits properly into the base of this multi-tap antenna.
<p>
I took it out into a local park, put the antenna with the lead on 40m, bolted it to my boot-lip mount, halfway pulled out the tuning end, a little metal spike that you can use to adjust the length of the antenna and turned on my radio.
<p>
Guess what happened next?
<p>
Nothing, that's what happened.
<p>
I was stunned, into silence, imagine that, me silent.
<p>
It worked. No adjustments, no trimming, no fixes, nothing. Just plugged it in and it worked.
<p>
Propagation was pretty poor, so no contacts as such, but oh my.
<p>
The point of all this is that when you least expect it, a surprise might come your way. Look at the assumptions you've made in your shack, think of the things you've tried and failed to achieve and use that to take a fresh look at what you have.
<p>
Hopefully your delight will be just as surprising as mine was.
<p>
I'll be back on air a lot more, who know's I might even get the opportunity to have a chat with you.
<p>
I'm Onno VK6FLAB
Listen:
Harmonics and calling CQ
Foundations of Amateur Radio
<p>
Have you ever had your radio on, listening around, say on 40m and heard the following:
<p>
"CQ, CQ 40m, this is VK6FLAB, calling CQ 40, CQ 40m, calling CQ"
<p>
Apart from the fact that the station calling seems pretty desperate for a contact, you're tuned to 40m, why on earth would you actually mention that, what's the point of telling me what band you're calling on, when clearly I'm hearing you on that band?
<p>
The answer to this question is in harmonics.
<p>
At the heart of every radio is an oscillator, set to some or other frequency that forms the basis of all that happens around it. In order to arrive at different frequencies, we add and subtract, double and halve frequencies, all combining to arrive at the various frequencies and bands we use.
<p>
I'll use some fictitious numbers here to give you an idea of what's happening.
<p>
Imagine that you have a 3.5 MHz oscillator. With it you can double it to 7 MHz, double that to 14 MHz, double it again to 28 MHz, that's 80m, 40m, 20m and 10m, just by using doubling. You could use the same oscillator and a doubler with a frequency tripler to get 21 MHz and so on.
<p>
A side-effect of doubling and tripling frequencies is that this process isn't perfect or linear. This in turn means that some of those imperfections also get doubled and tripled.
<p>
These imperfections are called spurious emissions and we reduce them as much as possible; in fact it's required by legislation to be below a certain level below the wanted emission.
<p>
As technology improves, these spurious emission standards evolve. The US FCC as an example says that for radios built before January 1, 1978 they're exempt, radios until 2003 must be 30 dB below the wanted emission and current radios must be 43 dB below.
<p>
What this means is that in effect your radio is transmitting on multiple frequencies at the same time, but filtering prevents most of this from coming out.
<p>
Now, imagine that you have a series of dipoles connected to your radio, one for 160m, one for 80m, one for 40m, one for 10m, etc. Imagine that your radio was built before January 1, 1978 and you're calling CQ. The harmonics are being generated, and because you've got an antenna connected that can transmit those harmonics, they go out into the wide blue world outside.
<p>
It's entirely possible that someone listening on 20m, 15m or 10m is hearing you calling on 40m through your spurious emissions at some or other harmonic.
<p>
So, next time you hear a station calling CQ 40m, they're either rusted on die-hard amateurs on a modern radio, or they are using a so-called boat anchor, having fun on air.
<p>
Either way, it's a great idea to say hello while you have the opportunity. Perhaps even use the experience as an excuse to learn more about their station, or even check out their harmonics and let them know if you can hear them. Propagation be damned.
<p>
I'm Onno VK6FLAB
Listen:
Lower and Upper Side Band, why is it so?
Foundations of Amateur Radio
<p>
Today we enjoy radio using all manner of different so-called modes. The ones that most people are familiar with are FM and AM. In fact digital radio DAB+ is another example of a mode. In Amateur Radio we have a few more to play with, Single Side Band, or SSB, countless other digital modes, CW, or Carrier Wave are all different approaches to getting information from one place to another.
<p>
If you have a radio that uses SSB, you'll soon notice that there are two versions of SSB, something called LSB and something called USB, or Lower and Upper Side band.
<p>
If you tune around the bands you'll soon notice that some stations are using Lower Side Band and others are using Upper Side Band and there seems to be no rhyme or reason to it.
<p>
Actually, there is a method to the madness. First of all, commercial and military HF radio all use Upper Side Band all the time. Radio Amateurs are a bit more traditional and we have the following basic convention. For voice signals on frequencies lower than 10 MHz, we use Lower Side Band, and for signals above 10 MHz we use Upper Side Band.
<p>
There are exceptions to this. RTTY, one of the digital modes uses Lower Side Band regardless of frequency and all the other digital modes use Upper Side Band.
<p>
Confused yet?
<p>
Here's another way to think of it. Everyone uses Upper Side Band, except for RTTY and Voice below 10 MHz on Amateur Radio.
<p>
Why are we doing this cookey thing to ourselves in Amateur Radio? First thing to note is that it's not random, we didn't just wake up one morning with this idea and said, lets do that.
<p>
Side Band was first figured out mathematically in 1914. A year later it was made into reality by John Carson who used it to carry more long distance telephone calls across the AT&T phone system. There were on-air experiments and in 1933 the ARRL board instructed the technical staff of QST magazine to investigate the feasibility of single side band carrier-less phone transmission on amateur frequencies. There is lots to read about this in the January 2003 edition of QST magazine, if you're interested, it's a fascinating read.
<p>
From an engineering perspective, radios built during the birth of Side Band, or Single Side Band Suppressed Carrier, to give its full name, used different methods to create a side band signal. One method was to filter out the part of the side band you didn't want, the other was to use phasing to add or subtract two signals and create a side band signal. Creating a filter was hard, creating a phase difference was much simpler to achieve.
<p>
Now, one of the effects of using this method of making a side band signal was that you had a place where the signals would add and another where they would subtract. Where was this place you ask?
<p>
One guess.
<p>
10 MHz anyone?
<p>
So, for these radios built during the birth of side band, Upper and Lower Side Band came as a side-effect of creating a simple and reliable system to make the signal.
<p>
Today we have alternatives which make this 10 MHz magic spot pretty much obsolete, but there are still 1951 Collins 75A-1 radios on air today and we like to talk to each other, so why fix something that isn't broken?
<p>
That's why we use Upper and Lower Side Band. Remember, everything uses Upper Side Band, except RTTY and Amateur Radio phone below 10 MHz.
<p>
I'm Onno VK6FLAB
Listen:
Logging software ... what to choose?
Foundations of Amateur Radio
<p>
Today I'm going to talk about housekeeping, that is, the things you should be doing while you're doing the things you like doing, like making noise on air.
<p>
The topic of Logging is one that continues to attract comment, suggestion, frustration and on occasion ridicule.
<p>
Let me start with the fact that the very first contact that I made was not logged. I can tell you exactly which day it was, Sunday, April 17. I can tell you where I was, Stirk Park in Kalamunda in Western Australia. I can tell you that the other station was a Japanese station, but that's all I can tell you. I don't know the time, the band, likely 10m or 15m, I couldn't tell you their callsign, even though I'm pretty sure that I wrote it on a random piece of paper at the time. It simply hadn't occurred to me that I should actually log that contact, or that I'd ever think back to that day and wonder whom I spoke with.
<p>
So, if you've not yet been on-air, get your logging sorted out now. It doesn't have to be fancy, it can be your diary, a notebook, a binder, or a phone, tablet or computer with appropriate software, just actually start logging. Do it today.
<p>
That out of the way, getting the entries stored somewhere, you'll soon notice that there are tools you love and tools you despise and that over time this changes. It also changes for different activities. If you're on the top of a summit or in a national park, you might just want a small notepad to log your contacts, but if you're in the middle of a contest you might just want to not have to worry about logging everything manually, you might just want to punch in the other station's callsign and their exchange.
<p>
The point is that for every amateur activity there are different aspects of logging. If you're chasing island activations you'll need a spot for the IOTA number, but if you're actually on the island, others are chasing you, then a good contest log is likely all you'll need.
<p>
So, I just said the magic word, good. What is a good log, what does it look like, which software should you look at?
<p>
Well, as in everything in life, that depends. You're likely to change logging software across your amateur activities, either because you have come to dislike the one you're using, or because it no longer works on the current version of your computer, or any number of other reasons. When you're picking software, you should as the very first priority discard all logging software that does not allow you to export the log. If you cannot export, you're locked in and your data is very possibly lost at some point in the future, so only use logging software, if you're using software, that does an export.
<p>
Now I did mention that you don't need to use software. Paper is perfectly fine, just a little harder to use if you want to check back and see when you worked a station more than once. It's also hard to use, actually, impossible to use, if you want to use Logbook Of The World, eQSL, clublog or any number of online contact verification tools.
<p>
If you're looking to log during a contest, figure out if the contest is actually supported by the software, this will help you reduce the number of contacts you make that are invalid. For example, a contest might specify that you can only work a station every two hours. Relying on memory is not a good plan. Using a computer to do that is much more productive and reduces the number of contacts that are going to be tossed out by the contest manager - not to mention that some contests apply penalties if you log an invalid contact.
<p>
A log that requires you to type in the frequency once is fine, but not if you need to type it in each time. If you're doing that on your phone, it'll get very tired very quickly.
<p>
If your logging software won't work without an Internet connection and you're away from the net while being set-up as a portable station, you'll have all manner of issues, so consider that.
<p>
So, what do I use?
<p>
For most of my contest activity, at the moment, I use VK Contest Logger. It's somewhat frustrating to use on a small sub-note book, but it's pretty stable, allows multiple computers to talk to each-other and share band information, allows export, is lightweight, regularly maintained and runs on most Windows computers. My actual station log on my Linux Desktop is using CQRLOG which I use to remove duplicates and enter QSL information, export to Logbook Of The World, eQSL and the like. I use a notepad when I'm mobile chasing DX and enter the data in my station log. I've used WINTEST during contests, played with HRD and still have not found one that works well on my phone.
<p>
It's a moving feast. I have different operating systems, Windows, Macintosh, Linux and Android, each for different purposes, but I've yet to find a universal one that integrates well across all that.
<p>
What ever solution you pick, make sure you log your first contact.
<p>
I'm Onno VK6FLAB
Listen:
What can you say on-air?
Foundations of Amateur Radio
<p>
There are things to say and things not to say as a radio amateur.
<p>
Let's start with swearing on-air. Each jurisdiction is different and changing. The Australian Radiocommunications License Conditions Determination, or LCD has nothing to say about content. It's all about bandwidth, frequency and modes. The rules in the USA discuss "obscene or indecent words or language", but there is no definition of what that might mean. A word in one country is meaningless, where in another it's completely unacceptable.
<p>
Our station signals travel around the globe, so it's prudent to moderate your language and to refrain from creating a situation where offence might occur.
<p>
Of course, there are those who take this to the n'th degree. There is a perception that you cannot use the words K-Mart or Target on air, instead referring to these locations by some euphemism. There is nothing in the rules saying that you are prohibited from stating that you purchased a tube of SWR grease for $1.49 from Target, but if you're using the bands to tell your fellow amateurs that you're offering a two-for-one deal on your pork chops because you're a butcher during the day, that's considered an advertisement and is prohibited.
<p>
There is no prohibition on language about sex, religion or politics, but that doesn't make them good topics of general conversation. That doesn't mean that you are not allowed to discuss them on-air with a mate, it means that you should really think about it if you're raising this as a topic in a net. Keep remembering that there are people from all walks of life, across the globe, who can hear you.
<p>
There is a funny clause in the Australian LCD, and I wouldn't be surprised to learn that it also exists in some form in other jurisdictions. Here, it states that the licensee must not transmit any form of entertainment. In Australia this is explained as not permitting music, but that is not actually a word that occurs in the conditions. It does occur in the USA and no doubt there are variations within other jurisdictions.
<p>
This "entertainment" clause is about broadcasting. There is an attempt to distinguish between commercial on-air use, that of a broadcaster, and amateur use, that of a licensed amateur.
<p>
The way it's worded in Australia is funny though. Am I entertaining you right now? Are you listening to this on-air? Am I currently in breach of the Australian licence conditions, or is the station that is transmitting my voice? To put your mind at ease, this is covered under another section, the licensee must use an amateur station solely for the purpose of transmitting news and information services related to the operation of amateur stations.
<p>
The two clauses that I just mentioned, the entertainment one and the news and information one, are all part of the same section, so you need to read the whole bit to understand what's going on. Of course that won't stop complaints or other interpretations, but so-far, that's all we have.
<p>
While we're on the point of describing what's proscribed and what's not. The Australian conditions say nothing about how to sign if you're operating portable. There is no rule that says that you have to. There is a document called "Amateur operating procedures" that states that the "information, about the operating procedures for the amateur service, can help prospective amateur operators studying for amateur exams". It suggests that you use the locality when you're saying your callsign and if you're using CW, it suggests a stroke and a number. This is why we have this proliferation of different ways of communicating this information. Stroke mobile, Stroke portable, Stroke QRP, Stroke VK6 they're all made up. None of them have any official status. Your callsign is just that, your callsign.
<p>
That's not to say that it's not helpful to add that you're portable, mobile, on a bicycle or standing in the ocean, but it's not part of your station identification.
<p>
There used to be a special endorsement for an amateur station to permit it to transmit television signals. It involved a Stroke-T as a suffix, but that was discontinued.
<p>
This means that what you say on-air is part regulated, part folklore and part common sense. Unfortunately where the edges of those three are is less than precise.
<p>
I'm Onno VK6FLAB
Listen:
QRP - When you care to send the very least!
Foundations of Amateur Radio
<p>
Today I'm going to talk about QRP, a term that's used in various different environments and one that I've used in the past. So, let's start at the beginning. QRP is a three letter code, part of the so-called Q-codes, that can either be a question or an answer. It's used in Morse communications to either ask "Shall I decrease transmitter power?" or to answer "Yes, decrease your transmitter power." It was perfectly valid for a kilowatt station to ask: "QRP?" and for another kilowatt station to answer: "QRP".
<p>
Language changes over time, meanings get inverted, changed, adopted and transformed. The three letter combination, Q-R-P, is no different. Today in Amateur Radio, the three letters are more like a word, rather than a code and the meaning has changed to indicate that a station is running low power or as an indication to others that they're likely to be a weaker signal that requires a little more effort to pull out of the noise than any other station.
<p>
As you might know, propagation is a fickle friend. There are days when you cannot talk to the station up the road and other days when you can hear a low power station clear across the globe and everything in between. The assumption that a QRP station is always hard to hear is not set in stone and often is quite incorrect. That's not to say that people think it's low, they hear QRP and think: "Hard work".
<p>
It's a bit like fishing for trout. Some days are good, other days are just wet.
<p>
Another aspect of the concept of QRP is the amount of power. The definitions differ. There are some that say that any station using 10 Watts or less is considered QRP. Others set the bar differently at 5 Watts. The ARRL defines it at 10 Watts or less for SSB and 5 Watts or less for CW or Digital. The WIA website uses a generic 5 Watts on their Low Power Radio page and different contests have different definitions of QRP.
<p>
It's clear that there is no single definition of what constitutes QRP, just that it's low power.
<p>
For me, I use 5 Watts and call myself a QRP station.
<p>
Should you tell the other station that you're QRP? Should you include /QRP in your callsign and say something like, this is VK6FLAB/QRP.
<p>
It depends.
<p>
There are times when my statement of QRP got me through a pile-up and other times when some smart calling didn't require me to mention that I was only using 5 Watts. I've noted in exchanges that I'm using 5 Watts and had positive responses. There was a time when I signed specifically with VK6FLAB/QRP, but it causes all manner of grief with confirmation of your contact, since some stations will log the /QRP and others won't, since it's not an official callsign suffix.
<p>
So, QRP is a wonderful aspect of our hobby, it teaches you to learn about propagation, to get your antennas sorted out, to pick your times and to learn better operating procedures.
<p>
I find it immensely satisfying to make a contact with my 5 Watts and there are times I wished my radio would go even lower than 5 Watts.
<p>
I know of amateurs who have worked across the globe, that is, the opposite side of the world, the furthest they can get with just a milliwatt SSB, so I know that while my contact from VK6 Western Australia to CO, Cuba with 5 Watts was proof that it all works, I know that there is more to explore.
<p>
QRP - When you care to send the very least!
<p>
I'm Onno VK6FLAB
Listen:
Coax impedence, 50 Ohm and 75 Ohm, why is it so?
Foundations of Amateur Radio
<p>
There is a recurring question that never seems to get a straight answer. Why are we using 50 Ohm impedance and not 75 Ohm? The more people you ask, the more answers you get. There'll be commentary about standing waves, SWR, loss, incompatibility, soldering, cost, velocity factor, diameter, susceptibility to noise and the list goes on and grows, the more people you ask, the longer the list.
<p>
Of course as time goes by, people remember stories told to them, guess, or even, how to say this, make stuff up.
<p>
To steal a phrase: "Why is it so?"
<p>
In the 1930's, when most of us were not even the apple in the eye of their parents - let alone their grand parents - coaxial cable was being developed for kilowatt radio transmitters.
<p>
There are two aspects to consider, the amount of loss against length and the ability of the coax to handle power.
<p>
Without going into the maths, there's plenty of that online, the lowest loss for air-dielectric cable is 77 Ohms. If we look at the peak power handling, that occurs at 30 Ohms, that is, at 77 Ohms, coax is best at getting signal across the cable with the lowest amount of loss and at 30 Ohms, coax is best at dealing with high power. Clearly a compromise is needed.
<p>
So, the mean between 77 Ohm and 30 Ohm is 53.5 Ohm and the geometric mean is 48 Ohm, so, 50 Ohm is a compromise between power handling and signal loss, for air dielectric.
<p>
So, obviously, 75 Ohm is used for TV reception and not for transmission. Except it ain't so.
<p>
In 1938, Roy Plunkett invented PTFE or Teflon. This material wasn't around when 50 Ohm was decided on.
<p>
If you remember, coax consists of a few parts, the centre and the shield, each conductors that we use to move our signal around and something in between, the dielectric, which stops the two conductors touching, with a cover over the top of that for good measure to protect against shorting and damage. The dielectric can be an air gap, or some form of plastic like PTFE.
<p>
Electrically, the dielectric constant for Air is 1, for foam PTFE it's 1.43 and for solid PTFE it's 2.2. Turns out that this makes quite the difference. Our lowest loss coax, is 77 Ohm for coax with an air dielectric, but drops to 64 Ohms with foam and 52 Ohm with solid PTFE. So, rather serendipitously, 50 Ohm was a grand choice, good power handling capability and low loss with a solid PTFE core.
<p>
Now, why are we using 75 Ohm for TV? One suggestion is that it's another compromise between low loss and cable flexibility.
<p>
What does all this mean for you?
<p>
In a nut-shell, 75 Ohm coax is one type of compromise, 50 Ohm coax is another. You can use either, but they won't be the same and won't react the same. Calculations made for one, will not apply to the other and loss and power handling will be different. This means that your roll of cheap Quad Shield RG6 is perfectly fine for some aspects of our hobby and not for others.
<p>
Here's an interesting tid-bit to tide you over until next we meet. If we compare RG58, common in Amateur Radio to RG6, common in TV, the losses are quite different. For 100m of coax, at different frequencies, these start to add up. At 1 MHz, the difference in loss is .6 of a dB, at 10 MHz, it's 2.2 dB and at 145 MHz, it's 10.7 dB. To be clear, the loss for RG6 is lower across the board.
<p>
This really means that you shouldn't be afraid to experiment. There is nothing particularly special about the different types of coax and each choice has it's advantages and dis-advantages.
<p>
I'm Onno VK6FLAB
Listen:
Q-codes in voice
Foundations of Amateur Radio
<p>
This week I'm going to have a look at something called a Q-code. Last week I talked about a few aspects of operating. One of the inventions associated with human speech is the short-cut, a way to quickly say something rather than use the whole story. Before Amateur Radio this started on the telegraph with shortcuts called Q-codes. Think a three letter combination, starting with Q, followed by two letters. QTH, QSL, QRZ, QLF are examples.
<p>
Language, just like Amateur Radio is an evolving feast. You'll find people writing articles about the abuse of Q-codes in speech going back to the early days of voice operation. The Q-code started with Morse Code as a way to quickly say something without needing to key the whole thing. This has flowed over into voice. You'll hear people use Morse-Code-isms in day to day language, 73, QSL, QTH and others are all examples of shortcuts that have no actual place in speech, but none the less have taken hold.
<p>
Having said that, of course there is difference of opinion how you should conduct yourself. I know that there are things I hear on air that make me wince, and I'm sure that I've said things that make others shake their head. So, here's my take on how it should be done and feel free to do the same, or ignore me altogether.
<p>
There is no such thing as "QRZ the frequency?". Nobody is calling the frequency. QRZ is specifically for the purpose of asking: "Who is calling me?" I know that there are some who are sharpening their pitchforks about now with all manner of comment, so let me be clear. I know, there are people who use QRZ in a pile-up. They've been calling CQ, had lots of replies, work a station and then after the contact say: QRZ?, with the meaning: "I'm done with the contact and I'm ready for another."
<p>
This in my opinion is particularly poor operating, since it means that you're too lazy to say your callsign, disrespectful of all the stations calling you, arrogant enough to assume that everyone knows which station you are and oblivious to the notion that propagation is ever changing with new stations dropping in and out all the time.
<p>
Instead of saying QRZ after such a contact, you're much better off saying your callsign instead. If you're in doubt, listen to some actually experienced contesters or DX operators and then you can you can fire off your feedback.
<p>
I've been told that I have a habit of overusing QSL, but it means: "Transmission received and understood." and in communications there cannot be too much of that. I use it in day to day on-air language, use it in email and SMS and when I'm proficient in Morse, no doubt I'll use it there too.
<p>
There are those that say that Hi-Hi, should not be used in voice, in Morse it's .... .. .... .., which sounds a little like someone laughing, which is where it comes from. Personally I think it's cute that you say Hi-Hi, even if someone who's not an Amateur doesn't share the joke.
<p>
As a stick in the mud, I dislike 73's. If you're going to abuse a code, then at least use the correct one. It's nice in Morse, --... ...--, symmetric, the end of a contact, all fine. But there's not more than one of them and we're not sending off the number 3, seven times, so drop the 's'.
<p>
I've been using language associated with broadcasting for a long time and I confess to wincing when I hear "Car-ah-be-an", rather than "Ca-rib-be-an", or "ad-ver-tise-ment" vs. "ad-ver-tis-ment" - no doubt some of my pronouncements will make you wince and some will find you agreeing.
<p>
I'm Onno VK6FLAB
Listen:
Operating Procedures
Foundations of Amateur Radio
<p>
Today we're going to look at operating procedures, that is, what to say, when to say it and when not to say it. Amateur Radio being over a century old has lots of traditions and lots of quirky exceptions to rules, but you'll learn those as you go on air and make mistakes, and assume that you'll make those, probably regularly and every now and then someone will gently correct you, or you'll get shouted at, either way you'll get feedback.
<p>
It's generally a better idea to figure out what's going on before you even open your mouth, so lets look at some things that really need to be second nature.
<p>
Your callsign is always last. Always! That way the other station knows who you are, every time.
<p>
I realise that you might not think that this is important, but just imagine that you've been inconsistent with this across your activities and one day you're in an emergency. Now it's crucial to know who is who. If you always do it the same, always your callsign last, then you'll do that in an emergency too.
<p>
That out of the way, there are other aspects to operating that you need to take into account.
<p>
You should always listen on the frequency that you're intending to operate. The longer the better. The reason I say that is because you may not hear both sides, or even two out of three, or more sides of the conversation. If there is a group talking, you may only hear one station who is happily chatting with others.
<p>
After listening, you should say: "Is this frequency in use?" and listen some more. After about a minute, ask again, adding your callsign: "Is this frequency in use, VK6FLAB". If you still hear nothing, you can say: "Nothing heard" and start your transmission on the frequency.
<p>
While you're operating remember that band conditions change and that you might find yourself all of a sudden among other stations that were not there earlier. They were, but you didn't hear them and you might actually find that they could hear you all along, so be prepared to make some new friends or make peace.
<p>
There are idiots on air. You'll find net controllers who all of a sudden turn up on the frequency that you've been operating on and demand that you QSY. You can argue the point, or you can take the high road and leave the frequency to those who think they own the air. No mileage to be made from yelling at each other, no benefit and you'll end up looking like the problem, even though no single station owns any frequency.
<p>
Similarly you'll find stations who have particular perspectives on how stations should operate and they'll go out of their way to tell you off. Pay no attention, unless they are actually going to make a formal complaint to your regulator, their feedback is just that, feedback.
<p>
If you hear a couple of stations talking to each other and there's a few stations you know, you can drop your callsign in between the gap between overs and if they're inclined, a station will acknowledge you and let you in. This in turn implies a gap between overs. Sometimes that gap doesn't exist. If it's urgent, you can try your callsign and understand that it may clash with another station, but don't force it and if you're in a group, leave a gap after the previous station hands over to you.
<p>
If you hear two stations discussing a medical issue, family affairs or other topics that are not generic, listen, but don't but in. When they're done and said goodbye, you can try your callsign and see if they respond, but don't expect it.
<p>
Next week I'll take a look at Q-codes.
<p>
I'm Onno VK6FLAB
Listen:
Lucky Lightning Escape
Foundations of Amateur Radio
<p>
In the past I've talked about our hobby and lightning. I've done it on more than one occasion, talked about cows and lightning strikes, about earth bonding and the dangers associated with lightning that's not directly overhead, but close enough to matter.
<p>
On the weekend I learned the difference between saying something and seeing something.
<p>
A group of Amateurs, went out camping, about two hours from anywhere in the middle of the bush to participate in an annual field day. We'd set-up our various overnight shelters, erected two marquees and proceeded to construct our portable shack. We were there for two nights. On the first night, the heavens opened up and the rain poured down, soaking the ground good and proper. We were lucky, our camp was at the top of a hill and drainage was great. At one point in the middle of the night I was standing outside in the rain, getting wet while attending to some ablutions - an unforgettable experience, but I digress.
<p>
The next day the camp was in full swing. We were on air and operating, making contacts, despite the poor levels of propagation. We'd erected an 80m dipole, 40m of wire in the air, a 2m vertical, a G5RV antenna and some other wire antennas. Each of these had a piece of coax coming into the marquee and strung along the roof made their way to the appropriate radio.
<p>
At that point the sky turned grey and thunder was heard. It was still dry, no actual activity overhead, or even within anything that could be considered nearby. As a precaution we disconnected our coax and settled down to wait for the impending storm. It never came. Other amateurs and house-holders were not so lucky, experiencing flooding and damage that was described as epic.
<p>
Meanwhile back at our portable shack, we decided that it would be smart to separate power and coax a little. We started by pulling back the coax and moving it back into the roof space of the marquee. At one point, one of our team had his hand on the metal marquee frame and pulled at the coax connector that was feeding the 80m dipole. The next moment a crack was heard, he jumped. He's experienced a significant discharge between his hand and the coax.
<p>
Remember, it's not raining, there's a grey sky and thunder can be heard in the distance.
<p>
Looking back, I still cannot believe that between us, five Amateurs with a combined experience level of about 90 years between us, moving coax around while there was lightning in the air. What were we thinking?
<p>
We were very lucky last weekend. It could have been much, much worse.
<p>
I'm Onno VK6FLAB
Listen:
The CAT interface
Foundations of Amateur Radio
<p>
Today's Amateur Radio is less like the valve or transistor based radio and more like a computer. So much so that most radios today have a mechanism to connect the radio to a computer.
<p>
This mechanism is called a Computer Aided Tuning interface, or CAT interface. It's a mechanism that's used to allow two way control information to be shared between the radio and a computer.
<p>
This interaction is a serial connection, generally something called RS232. This is a standard that was developed in 1962 and it specifies things like timing, voltages and other attributes. The electronics from that era don't look much like the ones of today and most of the challenges with getting this stuff to work is related directly to these differences.
<p>
It should come as no surprise that each manufacturer has their own take on what this whole contraption looks like and most of this technology is not directly compatible across radios.
<p>
So, let's imagine that you've got a radio and a computer and they're physically connected to each other using a CAT interface of some description. We then need to make sure that things like the speed of both ends is the same, that is, the BAUD rate is the same. Also we need to check that the number of bits, stop bits and parity are also correct. If this sounds a little like 1980's modem talk, you'd be correct. The radio is presenting itself to the computer as a serial device, just like a dial-up modem does. If you've not seen this, just think of it as if the numbers at both ends need to match. Often the radio will have a standard setting, which you should use as a starting point.
<p>
Now, I'm going to skip over things like IRQs and port addresses, not because it's simple, but because it might work out of the box, or it might cause you to lose hair. If it's the latter, you're going to need to do some IT support and this is about radios and not about computers.
<p>
I'm also going to gloss over the problem that most modern computers don't have an actual serial port any more, most have something called USB which requires an adapter and software for the adapter, another potential minefield to traverse.
<p>
Now comes the bit where it all works, right? Nope. Not yet. Next you need to have software that knows how to talk to your radio. It may be programming software, specifically to configure your radio, or it may be generic logging software that reads what mode and frequency you're on and puts that in your log, or it may be something that knows how to correct the frequency of your radio to deal with the Doppler effect of an overflying satellite.
<p>
In each case, you'll need to tell your software several things. The most basic one of those is the port number. That is, of all of the serial ports on your computer, which one is connected to your radio?
<p>
Seeing that all Amateur Radio manufacturers agree on everything, all actual control codes and responses are the same across all radios. Oh wait, nope, that's not true. They're not even the same across the same brand, so you'll also need to tell your software which actual radio you're using, which is the perfect opportunity to learn that your shiny new radio doesn't yet exist within the software.
<p>
So, when you start looking at the CAT interface, you now know that this is a thing that's going to require some homework and planning.
<p>
To make digital modes work, you need an audio interface to go with the CAT interface, which a whole different set of fun and games, including ground loops, impedance matching, levels, feedback and distortion.
<p>
Now, if you thought that you and I took a lovely walk through the deep arcane world of serial computer interfaces, wrap your head around this.
<p>
When we use the current crop of software defined radios, we replicate all of this, both CAT and audio interfaces with virtual versions of cables, BAUD rates and port numbers. Suffice to say, I don't have words.
<p>
I should add that all of what I've said is just so you get an idea that there is a chain of stuff that needs to work and that any one of these being incorrect will cause none of it to work. So, when you're doing this in your own shack, start at the beginning, get the cable working, set the speed and bits, set the port, pick the radio and cross your fingers.
<p>
It's not trivial, but it's worth it.
<p>
I'm Onno VK6FLAB
Listen:
Bandplans and Edges
Foundations of Amateur Radio
<p>
Today I'm going to talk about operating procedures. Before groan and tune out, stay with me for a moment, this is important for all amateurs, even you.
<p>
We as amateurs have a range of bands allocated to us. These bands cover a whole chunk of spectrum that we in many cases share with other users. They might either share the same band with us, or the other way around, we with them. Our bands might be right next to theirs or overlap in some part.
<p>
To make things more interesting, these bands are unfortunately not uniform across the world. For example, in Australia part of IARU Region 3, the 40m band runs from 7.0 to 7.3 MHz. In Region 2, it's the same, but in Region 1, it only covers 7.0 to 7.2 MHz.
<p>
If you look at the 80m band it's worse: Region 1 uses 3.5 to 3.8 MHz, Region 2 uses 3.5 to 4 MHz, Region 3 uses 3.5 to 3.9 MHz, but in Australia we can only use 3.5 to 3.7 and 3.776 to 3.8 MHz and that last little bit, the DX window, only if you hold an Advanced License.
<p>
This can have profound implications for your operation on air. If you hear a station, clearly an amateur, callsign, working a pile-up and doing everything right, you may not actually be allowed to work them, even if you're privileged on the band you're listening on.
<p>
Things get tricky near the edges of the bands. If you're operating near an edge, you are not allowed to have your signal stray across the band edge, so if you're using an SSB signal, the frequency shown on your radio is not where the edge of your transmission is, the radio is showing where the carrier is, the side-band signal depending on the type, can be another 2.5 to 6 KHz up or down.
<p>
So, that's simple right. If you're using a band that uses Lower Side Band, say 80m, you can slide on up to the upper band-edge and start operating right?
<p>
Uhm. No. Couple of things. The other side of the side-band doesn't vanish, it's reduced. Depending on the quality of the radio, the reduction is better or worse. Using an amplifier makes this problem bigger. Some radios have good filters on both transmit and receive which changes the picture again. I've not even talked about spurious emissions, harmonics and other artefacts which muddle this picture even further.
<p>
The take-away for this is to make sure you know where the band edges are for your station and to make sure that you know what the performance of your actual radio is and where it transmits.
<p>
I'm Onno VK6FLAB
Listen:
What's in a Repeater?
Foundations of Amateur Radio
<p>
Today I'm going to talk about repeaters. These invisible services that sit on a particular frequency and do magic things to your signal.
<p>
First of all, the best way to think of a repeater is to think of it as two radios. One is the receiver, the other the transmitter. The way it works is that the receiver hears your signal and sends that audio to the transmitter which sends it out over the air.
<p>
For this to work, there need to be two frequencies in use, the one that you're transmitting on and the one that the repeater is transmitting on.
<p>
From this simple idea, many different things flow. There is no rule that states that the receiver and the transmitter need to be in the same place, let alone on the same band; if they're on different bands, it's called a cross-band repeater.
<p>
If the receiver and the transmitter are on the same band, the system needs to deal with the fact that a strong signal is being transmitted by the repeater right next to where the receiver is. If you're not careful, the transmitter will overwhelm or de-sense the receiver, making it harder to get your signal into the repeater.
<p>
Several techniques are used, a contraption called a cavity filter is set-up to specifically let either the receive frequency through, or to block all frequencies except the transmit frequency. Some combine both of these techniques to make the repeater hear weak stations better.
<p>
If the receiver and transmitter are on the same band, the difference between the two frequencies in use is called the offset. It varies per band. On 2 meters, the offset is normally 600 kHz, but it varies, on 70cm the offset is 5 MHz, but on 10m, the offset is 100 kHz. So different bands use different configurations and of course each of these is subject to local variation. There may be local interference on the standard offset, so it may be varied.
<p>
There are some other things going on with repeaters. You can have a repeater that receives and transmits on the same frequency, it's called a parrot repeater and it sits there waiting for you to transmit, stores the incoming audio for a set period and then when you stop transmitting, it sends out the audio on the same frequency. This is useful to see how you sound on-air.
<p>
Other techniques include adding computers to create IRLP, Echolink and AllStar Link. Essentially the receiver is connected to a computer which sends the audio across the Internet to another computer which in turn sends out the audio to another transmitter. After you stop transmitting, the chain is reversed and the other station can talk to you via a reverse path.
<p>
There are also specialised repeaters that can listen in one mode, like FM and transmit in another, like AM, or SSB. This allows a 2m user to use HF from their FM hand-held radio.
<p>
If all that's not enough, there are other things possible with repeaters. You can use a special tone to identify to the receiver that your signal is a valid audio signal. This is used in environments where noisy local signals often trigger the repeater, resulting in ongoing kerplunking of the transmitter.
<p>
Next time you key up your local repeater, have a think about what's happening when you key-up your radio and say thanks to the owner of the repeater who spent time and effort, not to mention money, to make this invisible friend on the air work for you.
<p>
I'm Onno VK6FLAB
Listen:
Experimentation is about failure ...
Foundations of Amateur Radio
<p>
There is an interesting phenomenon that I've begun to notice and now that I've seen it, it's hard to un-see. Think of it as the equivalent of the little dot in the top right corner of the screen that signifies the end of the reel to a movie projectionist. Once you've seen it, you can't miss it ever again. If you haven't, sorry, you will and now you'll carry that with you for the rest of your life.
<p>
Across Amateur Radio, from Foundation and Standard through Advanced or Technician and General though Extra, there is this thing where people get together and ask each other how to get started.
<p>
It's amazing to observe, grown adults every one of them, not daring to take the first step. It ranges from keying your microphone for the first time, through to making your first HF contact, through building an antenna, going portable, climbing a mountain, making contact with the International Space Station, doing a contest, building a radio or erecting a tower.
<p>
It seems that collectively we've forgotten that this whole thing we do is about experimentation. We're so wrapped up in failure that more and more I see people wanting reassurance that what they're doing is right. Like they have to somehow be perfect the first time, be amazing, be accurate, eloquent, sturdy, brilliant or whatever is going on.
<p>
I don't know how this started, but it's got to stop. If we extrapolate along this path we're going to end up as licensed automatons with no innovation, no spunk, no mistakes and no learning.
<p>
Don't mistake me. You're not alone, there is prior learning to be had and community knowledge to be gleaned, but if you never fall flat on your face, how will you ever learn to get up?
<p>
So, next time you're getting ready to do something, just start. Don't wait for validation, take failure in your stride and learn.
<p>
Last week a friend and I went to scout a new location for a field day contest. We drove there, set up our station and proceeded to spend the day failing. We got RF into the radio, the computer was barely readable in the sun, I got sunburnt, we made two contacts and had a miserable time with short power leads, hard to use trees and to boot, it was hot.
<p>
On the flip side, we trialled a new antenna design, learned that my clip on ferrite chokes don't and that we now had a list of things we'd learned and stuff we needed to bring when we came up for real.
<p>
We didn't go up there to fail, we wanted to activate a rare WWFF Park, but instead we failed and learned other stuff.
<p>
Think of this whole thing in a different way, frame it not as success or failure, but frame it as a way to learn something. Edison had this to say: "Negative results are just what I want. They're just as valuable to me as positive results. I can never find the thing that does the job best until I find the ones that don't."
<p>
Learning to experiment and being an experimenter and having a license that says you're an experimenter is also about learning to fail. Don't be scared. It happens to all of us. The better you fail, the better you succeed.
<p>
I'm Onno VK6FLAB
Listen:
What is the best antenna?
Foundations of Amateur Radio
<p>
The single largest topic of conversation in Amateur Radio is about Antennas. The discussion often starts with one amateur telling another amateur about some or other amazing antenna, followed by a heated discussion about the merits or pitfalls of that same antenna and why they would never ever consider using it and why it's a waste of money, or some other rationale.
<p>
Let's take for example the discussion of Dipole versus Vertical. There are those who will tell you that they'd never ever use a Dipole and similarly those who'd say the same about a vertical. Assertions of suitability aside, let's have a look at what we're talking about, first of all.
<p>
In rough terms, a dipole is an antenna that is generally suspended between two sky-hooks, its fed from the centre and has pretty much an omni-directional radiation pattern. That is, signals arrive and depart from this antenna, pretty much evenly in all directions. Now, before you get all excited. It's not exactly the case, since it's not an isotropic point source, which you might recall is a theoretical antenna that we can prove not to be physically possible, but a dipole is the next best thing.
<p>
A vertical is an antenna, which is often supported from a pole of some description, has some form of radial ground-plane at the base and while it's also omni-directional, there are parts of the signal that don't arrive nearly as well and other parts of the signal that fare better.
<p>
Often a statement when comparing a dipole to a vertical will be something like this: "A vertical is better for DX and a dipole is better for local contacts."
<p>
Now, let's just investigate that for a moment. If you've ever seen the radiation pattern for a vertical, you might have seen that there is a particular angle at which there is gain when compared to other angles. What this means is that signal arriving and departing from the antenna in essence favour that angle. Similarly, a dipole doesn't display this phenomenon nearly as sharply. There is some asymmetry between the sides and the ends of a dipole, but it's not particularly strong. Not that it's non-existent, just not pronounced.
<p>
If you were to overlap the radiation pattern of a dipole and that of a vertical, you'd notice that apart from the single angle where the vertical favours radiation, the dipole pretty much has the same level of gain all round.
<p>
In essence, this means that to all intent and purpose, apart from a single little angle, the dipole is pretty much the same as a vertical.
<p>
I hear you say, "Yes, but..."
<p>
Indeed.
<p>
Think of a vertical as an antenna that favours a particular angle of incidence. It's more prone to hear signals from that angle than any other angle. Similarly, any transmitted signal is likely to favour that particular angle.
<p>
As you know, the ionosphere is a moving feast. Signals arriving at one angle one moment may not be arriving at the same angle the next moment. If your vertical hears a signal one moment and not another, does that make for an effective antenna?
<p>
Another aspect that separates a vertical from a dipole is the behaviour of vertical signals, so called NVIS, or Near Vertical Incident Signals. Things that are nearby. A vertical antenna all but ignores that aspect, where a dipole has no such behaviour.
<p>
So, we're getting to the heart of it, imagine for a moment that the differences between a vertical and a dipole is their difference in filtering of signals. That is, a vertical filters signals from above, where the dipole doesn't. Similarly, a vertical filters all but the bits from a particular angle of incidence, where a dipole doesn't.
<p>
If you've followed along, you might begin to realise that there is not a single "best" antenna. It's horses for courses. Your antenna choice is based on what you aim to achieve, not which antenna is better than any other antenna.
<p>
So, the question: "Which antenna is the best?" should really be: "Which antenna is the best for this particular activity?"
<p>
Something to try next time you have a chance. Get a two-way coax switch and hook up both a vertical and a dipole and listen to the same station with each antenna in turn. Take your time, listen throughout the day. You'll be amazed how they differ and how it changes over time.
<p>
I'm Onno VK6FLAB
Listen:
The humble dipole ... contraption.
Foundations of Amateur Radio
<p>
Today I'm going to talk about dipoles. You know the tried and true antenna, the go-to design for getting on air, the simple first antenna you ever make, the one you learn from, you know the one. It's the mainstay of every amateur, of any field-day, of all things Amateur Radio.
<p>
It's a simple thing. Using metric, rather than imperial measurements, but the point stands, you use the speed of light in vacuum divided by the required operating frequency and you get the overall wave length for that frequency. In absolute terms, roughly 300 m/s divided by 50 MHz, gives you 6 meters. Surprise, that's the band name for 50 MHz.
<p>
Now the dipole is a half-wave contraption, so, 6 meters divided by 2 gives you 3 meters for your total half-wave dipole. Each leg is half that, a quarter wave length, so you have 3 meters divided by 2 again and you end up with two bits of wire, a meter and a half long each.
<p>
If you're following along, that's 300 divided by 50 divided by 2 divided by 2, or using the same numbers in a slightly different order, 300 divided by 2 divided by 2 divided by 50 MHz, or 75 divided by 50 MHz. Still one and a half meters per leg of your shiny new dipole.
<p>
So, the basic formula for a metric dipole can be stated as 75 divided by the frequency in MHz per leg. If you're playing with feet and inches, 300 m/s becomes 984 ft/s, half that is 492, half that is 246 feet, so the imperial version is 246 divided by the frequency in MHz, gives you length in feet for each leg.
<p>
So, you've cut your wires, tied them to some magical feed point contraption, plug it into your radio and you're good to go, right?
<p>
Now, anyone who's actually done this knows that this is not what will actually happen. It's never that simple, and frankly if it were, we wouldn't be Amateurs, we'd be, unlicensed or something.
<p>
So, what affects the actual length of this magical antenna? Lots and lots of things. Here are a few that come to mind:
<p>
- The thickness of the wire you're using.
- The thickness of the insulation on the wire.
- A thing called the end-effect.
- The height of the contraption above the ground.
- The kind of ground.
- The price of the copper you're using.
<p>
Sorry that last one isn't right. I have been told, time and time again that there are only two kinds of wire, cheap wire and free wire. The preference is for the latter. So, price of the copper doesn't matter. Another thing that does matter is that some wire can stretch while in the air, making the antenna longer, so keep that in mind.
<p>
Fine and well I hear you say. But how does this really matter?
<p>
If you increase the thickness of the wire, the resonant frequency goes down, that is, the antenna is "too long". If you increase the thickness of the insulation, the resonant frequency goes down as well. The end-effect is like adding a capacitor to the end of the wire, making it "longer" as well. The height effect is different for each height. Generally the effect is that the antenna resonates at a lower frequency. Each type of ground has a different amount of effect. Water vs rock vs sand vs clay.
<p>
I can hear you groan at this point.
<p>
First comment to make is that all of these effects make the antenna resonate at a lower frequency. This means that the suggestion to cut your antenna longer than the calculated number doesn't make much sense. If you start with the basic calculation, 75 divided by the frequency in MHz, you'll end up with an antenna that's extremely likely to be too long.
<p>
I can hear you screaming at me right about now. Hold your tar and feathers. I gave you the First comment. Here's a Second one.
<p>
If you don't have space for a straight dipole, say, you need to go around a corner, or put a bend in the wire, all of what I just said goes out the window. If you put this above a metal roof, poof, also out the window. If you cannot terminate the wire to a rope without bending the end of the wire, poof.
<p>
A Third comment. You cannot cut wire longer. You can only cut it shorter. Cutting it longer is called soldering and that's a whole 'nother thing.
<p>
Let me finish with some tips for new players.
<p>
Don't ever cut your wire. It won't work like you expect and it will only give you more work. Always, always, always, fold your wire back over itself and wind it back over the end. If you leave it dangling you're adding capacitance and doing all manner of other weird stuff to your antenna.
<p>
Also, if you need extra length because the 80m dipole just won't fit into the back yard, you can use the end capacitance to good effect, hang it down towards the ground and you'll end up with an antenna more to your liking.
<p>
Final comment and then you can start sending me emails about how I'm wrong.
<p>
The humble dipole antenna is a magnificent contraption. It has more variables than you can poke a stick at and anyone who tells you that it's just a case of calculating this by doing a simple division hasn't got the faintest idea of what's actually going on. There are times when simplification is helpful. This is not one of those times.
<p>
So, have fun, play with your dipole, try different things and observe the differences when you try different things. I've spoken with Amateurs who've been doing this longer than I've been alive and they still can't calculate the actual length of a dipole, put it in the air and have it work first time.
<p>
Sometimes you get lucky. More practice, more luck.
<p>
I'm Onno VK6FLAB
Listen:
Sizing your battery.
Foundations of Amateur Radio
<p>
Today I want to raise the topic of batteries. Specifically, sizing the battery.
<p>
You can do as I did naively, look at the manual, see that the current consumption of your radio is 22 Amp, decide that this means that you need to get a 26 Ah battery to use your radio for 1 hour. Being the portable type, I got two, 52 Ah in total.
<p>
Some time has passed since I made that purchase. I've learned that I can get a lot more out of my battery than 2 hours. I also learned that lugging 56 Ah around is not fun.
<p>
Having learned this, what could I have done to improve?
<p>
Well, first of all, the 22 Amp is for Transmit. According to the manual, on receive it's only using 1 Amp. If you're not transmitting all the time, then you're not drawing 22 Amp the whole time. The ratio between send and receive is the Duty Cycle, often expressed as a percentage of the time spent transmitting.
<p>
Another thing to note is that 22 Amp is when you use full power for a particular mode and band combination. On my radio that's 100 Watts, HF FM, so only using 5 Watts will reduce the power consumption radically. Speaking of which, my radio has different maximum power levels for different bands, so when you're doing the maths, you need to take that into account.
<p>
If that didn't add enough complexity, different modes use different amounts of power. AM, FM, RTTY and other digital modes use 100% duty cycle. CW uses 40% and SSB only 20%.
<p>
So, rough back of napkin calculation, using 5 Watts SSB on HF for an hour, transmitting only half the time gives you 22 Amps times 5% power, times 20% SSB, times 50% of the time, a 10th of an Amp.
<p>
Now, before you go out and buy a 1 Amp Hour battery and expect to use it on HF for 10 hours, there are some wrinkles. First of all, a 12 Volt, 26 Amp Hour battery doesn't actually give you an Amp per hour for 26 hours at 12 Volt. It's graded on a scale. At the beginning it gives you a higher voltage, at the end it gives you a lower voltage and after a certain point you've actually destroyed your battery, not to mention that the radio stopped operating when the voltage went below 11.7 Volts - somewhere around 30% capacity.
<p>
To make things even more interesting, different batteries react differently depending on how fast you're drawing from them. Another issue is that temperature affects how much power you are able to draw.
<p>
After all that, the manual for your radio is specifying theoretical numbers, not actual ones. I've never ever seen my radio draw 22 Amps, even when it was running flat out. On the flip side, I've also never seen my radio draw less than 4 Amp when transmitting, so the maths for this doesn't add up as expected.
<p>
So, why was I giving you the maths if it doesn't work out?
<p>
Because the Simple Simon Says solution doesn't work, but neither does some educated calculation.
<p>
I hear you saying: "Well, that wasn't helpful."
<p>
Actually it was. Now I can tell you something and you'll know why it will help you.
<p>
Get yourself a power supply with a display that shows Amps, or get yourself an ammeter and stick it into the power supply circuit and take some measurements.
<p>
Use a dummy load as the antenna, since SWR will also affect these numbers, as does the microphone gain, the squelch level and the volume level, as well as the display on the radio, the tuner and other things you have connected.
<p>
Theory is great, practice in this case gets you a lot more reliable result.
<p>
I'm Onno VK6FLAB
Listen:
Where did all the amateurs go?
Foundations of Amateur Radio
<p>
There is a recurring topic in Amateur Radio circles, called "permissions", or "rights", or some other word indicating "entitlement". It's a conversation that has been happening since the dawn of radio experimentation and will continue until well after our Sun has burped it's final sun-spot.
<p>
In Australia, there are three classes of License, in increasing level of responsibility they are Foundation, Standard and Advanced. There is an ongoing tension between these categories. Some higher level responsible licensees look down on the class with less responsibility, and the reverse is also true.
<p>
This separation of class is an evolutionary one. As I said recently, the most recent overhaul, more than 10 years ago, back in 2005 saw the introduction of the Foundation Class and the consolidation of various classes into Standard and Advanced.
<p>
There are current noises being made about how this needs to change. There are those who suggest that the Foundation Class needs to have access to more power, to more bands, to more modes and various other suggestions. There are recurring noises of making the Foundation Class require a renewal and other such things. Often there is some link made to the growth of the hobby. Make it simpler so we can get more people, make it bigger so we get more people, make it harder so we get better people, make it ... something else.
<p>
I'm a computer geek. I like playing with data and I like to figure out how stuff works. Over a year ago I started the process of trying to understand how amateur radio ebbs and flows. For example, in rough terms, in the 10 years that the Foundation Class of license has existed, we've issued about 10,000 new licenses, so around 1,000 a year, give or take.
<p>
In the same time, the total size of the amateur community has stayed pretty much the same.
<p>
So, did we loose all those Foundation entrants, did the old ones die off, did something else happen? Is a licensee who starts and stays for a year more or less likely to upgrade? Is there a time window when the likelihood of dropping out is increased? Is there some underlying factor that causes people to leave the community? Is there a correlation between on-air activity and longevity in the hobby? What about age, gender, etc. We simply don't have the analysis at this time.
<p>
I've been at the ACMA and the WIA to get access to historic data, frankly it's been a hard slog, the ACMA pointing at the WIA and the WIA claiming license restrictions and neither giving any indication that they're doing anything to resolve the issue. In case you're wondering, I'm talking about the public RADCOM, now called SPECTRA database, nothing secret or private about it.
<p>
I recently hit on the idea of using contest logs from the various contests to determine actual on-air activity. So that will add several gigabytes of data to my investigation. And an interesting side note - based on incomplete data, the 2015 CQWW Phone Contest saw the submission of 60 logs from Australia, but around 750 actual stations from VK were heard on-air. I'm attempting to get the same raw information from the local contests. This will give me a "Last Heard on Air" date, which will give me an indication of the status of the callsign involved.
<p>
So, regardless of where you stand on the notion of the amount of responsibility you have as a Licensed Amateur, it's clear to me that we need more information.
<p>
I think this is important for the future of our hobby and I'm working on it.
<p>
I'm Onno VK6FLAB
Listen:
Reviewing the introduction of the Foundation License.
Foundations of Amateur Radio
<p>
The history of the evolution of amateur licensing is a nebulous affair, told and re-told, moulded, changed and interpreted by the story tellers along the way. There is an on-going debate about how the restructure of the licensing regime in Australia, in 2005, has affected our hobby.
<p>
In 2005, after a 10 month review period, three classes of license were established, a new Foundation class, an a re-imagined Standard and Advanced class, using existing novice and novice limited licenses to create the Standard class and combining limited, intermediate and unrestricted licenses into the Advanced class.
<p>
I've touched on this subject before, back in 2011, when I noted that those who forget history are doomed to repeat it.
<p>
The ACMA published the review in May of 2004. It summarises the responses about the introduction of the Foundation licensing option.
<p>
It opens with, "Over two-thirds of submissions were in favour of the introduction".
<p>
It goes on to say that the most common reason for support was the need to make the amateur service more accessible and cited that the Foundation class then introduced in the UK was the appropriate standard.
<p>
The majority of respondents suggested that the maximum transmitter output should be 100 Watts PEP and suggested 80m, 40m, 15m, 10m, 6m, 2m and 70cm as the appropriate bands.
<p>
Also of interest is that 39% of respondents were in favour of a two-tier licensing structure, where 24% were in favour of a three-tier structure.
<p>
The ACMA report also mentions that many respondents suggested that the foundation license should not be renewed without the licensee being re-examined.
<p>
If you're familiar with the restrictions and obligations of the Foundation License then you'll recognise that some of these responses were agreed to and some rejected. I've not included the full report, it goes to 15 pages, but there are some other interesting things in the ACMA report.
<p>
The ACMA notes that the main reason cited for requiring a Foundation licensee to be re-examined was to promote the license as a "stepping stone" to amateur radio operation. It notes that while there are provisions in the Act for such a re-examination, where there are reasonable grounds to believe that a qualified operator would be unable to achieve satisfactory results. The ACMA notes that none of the current amateur licensing options requires an amateur operator to be re-examined regularly.
<p>
I wonder if we actually forced all amateurs to re-do their license, how many would actually pass? I know I would.
<p>
There are other interesting things afoot. There is discussion today about allowing Foundation Licensees to use digital modes, but there is a move to require that it be added to the syllabus before that is permitted. Of course there is a parallel to make, none of the current licensees have any such formal training, why should a Foundation Licensee be "special" and require extra training.
<p>
I've been asked what I think about privileges and the Foundation License. To be clear, I'm perfectly happy with my privileges. I have yet to experience all that Amateur Radio offers, and by turning my operating power to half the permitted level, 5 Watts, I'm learning specifically what works and what doesn't. I'm learning about propagation, about antennas, about operating techniques and about patience. I'm sure that this stands me in good stead wherever I go.
<p>
One final comment, the ACMA report references a submission by a group called CQVK. I managed to track down the 112 page submission and have uploaded it to the F-troop website, the home of the weekly net in which New and Returning Hams can get together every week. Have a look at the ACMA report and the CQVK report at http://ftroop.vk6.net.
<p>
As I've said before, those who forget history are doomed to repeat it. Let's not.
<p>
I'm Onno VK6FLAB
Listen:
How to manage your first pile-up.
Foundations of Amateur Radio
<p>
There are skills that come from thinking and there are skills that come from doing. There is place for both in Amateur Radio.
<p>
There is nothing in the world that is like the experience of working a pile-up, unless the trading floor of the New York Stock Exchange counts, but I've not personally been there and it doesn't look as intimate as a radio shack.
<p>
Working stations across the planet that are coming in thick and fast is an amazing thrill, not unlike getting onto a roller-coaster. The long slow journey to the top of the ride is calling CQ, the crest of the hill is the first response and the loop-de-loop is when they're all calling at the same time; rolling back down to earth at the end of the ride is the petering out of the calls, only to start again.
<p>
If you've never experienced it, I'd strongly recommend that you find a way to put yourself in the position where you are exposed to this absolutely thrilling experience.
<p>
So, what do you do when you're actually in this situation?
<p>
Hopefully you're not going to be on your own the first time, but it does happen and it might be that the person you're with has never had the experience either, so here's some ideas on what to do.
<p>
The first thing to remember, this is YOUR pile-up. You're the one running it, you're the one in control of it, it's your actions that make it work, or not.
<p>
I've said in the past, it's all about rhythm. It's about expectation management. If the pile-up sees you floundering about, not being consistent, not giving out succinct information, they'll go elsewhere and the experience will be over before it begins.
<p>
So. The noise is overwhelming, there are stations all over the place calling you. If you hear a callsign, or most of a callsign, then call that. Don't change your mind if someone else comes back instead.
<p>
You've called CQ and let's say that you heard, K1R. You call back, K1R, 59. If the station operator on the other end is any good, the response might be HK1R, 59 also. Your response will be HK1R. CQ VK6FLAB.
<p>
But lets say that you only heard K1. You call back, "the station with K1". The response is three stations at the same time, one SK1Q, one VK1AA, one JA7BG. You could get upset about the JA7 station calling, but remember, he too has lots of stations calling around him, he might not have properly heard either.
<p>
You say "the station with K1, K1 only please". Two stations come back. SK1Q and VK1AA. You pick the one you hear best. SK1 again. You hear SK1Q.
<p>
"SK1Q, 59."
<p>
If your memory is great, you could also go on to say "VK1AA 59" and then call CQ. This is not something you'd do on your first or 10th pile-up, but it's something to work toward.
<p>
The thing that took me a while to recognise is that there are idiots on the band who think that their callsign is the most important. My best advice is to ignore them. This is hard. They'll be very noisy. One trick, call while they're calling, rather than let their rhythm destroy yours. Remember, this is YOUR pile-up.
<p>
Other things to note. I've spoken in the past about the so-called standard phonetic alphabet. As you might remember, there is no such thing. This will trip you up. Don't let it bother you. Other fun stuff that happens in a pile-up, especially if it's been going for a little while, is that you notice little comments. You might inject one of your own. "HK1R Big Signal, you're 59". Or if it's a friend, K9CT, you might say: "K9CT, Hi Craig, long time no see, 59." It's the little inserts in the middle of a pile-up, in the middle of the night that make you smile and give you that shot of adrenaline to make it last longer.
<p>
I have to admit. For me, there is no stronger drug that riding a pile-up.
<p>
Of course, this is not all there is to learn about pile-ups. It's to give you some idea of what's going on and what you might do to keep it alive when it happens to you.
<p>
Feel free to get in touch with questions if you like.
<p>
I'm Onno VK6FLAB
<p>
This and other episodes are available online at http://podcasts.itmaze.com.au
Listen:
Have a look or search online at the previous editions of this podcast.
Foundations of Amateur Radio
<p>
This is episode 236 or so of my weekly contribution to this hobby. As you may have heard me say over the past few weeks, this is now available as a podcast which you can subscribe to. It's available at http://podcasts.itmaze.com.au and you can also search for my callsign, VK6FLAB on iTunes and find it there.
<p>
I'm mentioning this because each podcast also contains a transcript, which you can use to search the content. I've been doing this podcast since May 2011 and in that time I've covered many topics.
<p>
I get wonderful feedback from you about each segment, thank you, and I also get requests for content. Often new listeners ask me if I could talk about XYZ topic, and I'm finding more and more that in fact I have talked about such a topic.
<p>
That's not to say that I won't revisit a topic if I have information to add. For example, I was in the process of researching baluns, got distracted by word-use and will revisit. As I'm doing the research I'm realising that the rabbit hole goes deep on that particular topic, so I'm not yet at a point where I can say much about it other than to think of a balun as a maths tool for feed-point impedance, that is to say, a 6 to 1 balun will transform a 300 Ohm feed-point to a 50 Ohm one, similarly a 9 to 1 will do the same for a 450 Ohm feed-point. All fine and dandy, but why would you need a 1 to 1 balun. Or what's the difference between a voltage balun and a current balun, not to mention the bandwidth, the different material types, and on it goes.
<p>
So, I'm not yet at the point where I can distil the information to a three minute segment, but I will.
<p>
I've also discussed cows and lightning in the past. If you remember, if a cow is facing the impact point of lightning, they can die from the current that flows along their body from their front legs to their rear legs. Which is why you want a single point earth in your station.
<p>
I hope that you'll take the opportunity to have a look-see across the previous editions of this segment and find something to your liking.
<p>
I'm Onno VK6FLAB.
<p>
This and previous editions can be found online at http://podcasts.itmaze.com.au/ and are also available for download from iTunes and other podcast directories. Just search for my callsign.
Listen:
Contesting, something for everyone ...
Foundations of Amateur Radio
<p>
Previously I've discussed different aspects of contesting in relation to Amateur Radio. If you're unfamiliar with the concept, contesting is an activity where you test your station and skill against other amateurs. Unlike other contests where you're all in the same physical location, say a stadium, or an online playing field, amateur radio contesting is most commonly done from the comfort of your own shack.
<p>
Of course, as is true for everything in life, there are exceptions to this. There are contests where you're not in your own environment, say on a field day, at a contest station, or some other place, but I'll ignore these for the moment.
<p>
In most organised sports, and amateur radio is no exception, there are rules for participating. It should go without saying that you're expected to abide by the rules. Disqualification, bans, even life-time exclusions and revision of results can and have happened.
<p>
Contests are planned by different people and groups and vary greatly across the globe. Amateur Radio is a global pursuit, and contesting is a global activity. It can start as simple as making a contact every day, through to staying awake for 48 hours and making as many contacts as possible across as many countries as possible as fast as possible, and everything in between.
<p>
If you think about that for a moment, you'll soon realise that with so many different people organising contests, there is likely going to be one that tickles your fancy. There are several contests every weekend and often one every day.
<p>
People participate in contests for different reasons, to try their new station, to win, to get another country on their DX list, to achieve a distance record, to test their skill, to learn how to hear callsigns in noisy environments, to spend time on-air, to laugh with friends and to contribute to the hobby of amateur radio.
<p>
If you're new to our community, then contesting might be a scary proposition. You might not know what to do, or how to even start. You should know that your doubts were true for everyone you hear on air. We still haven't mastered the art of growing an amateur in utero, though I should confess that some act as if they are.
<p>
So where do you start?
<p>
The best way to do this is to set-up your station and to tune around the bands and to listen to what is going on. It will be confusing at first, but if you find a station that is making contacts that are different from normal ones, you know the one where you both exchange callsigns and a signal report, you'll begin to hear other parts of the contact. It's possible that the station is exchanging a serial number, or some other special token.
<p>
You can also go online and find many different amateur contest calendars which each will give you a way to find out what global activity is currently taking place, so you can look up the contest online and read the rules.
<p>
If all that's too hard, talk to your fellow amateur friends and go to their station and see what they do to participate in a contest.
<p>
I'm Onno VK6FLAB
<p>
This and other episodes of Foundations of Amateur Radio can be heard via podcast or download at podcasts.itmaze.com.au.
Listen:
SDR diversity and Ah-Ha!
Foundations of Amateur Radio
<p>
In every new technology there is an ah-ha moment, the single one insight that defines for you personally what this technology is all about. No doubt this happened when Amateurs first used valves, when they started using transistors and so on. For me that moment happened during the week.
<p>
You've heard me talk about the absurd noise floor, that is, the incredible amount of local radio noise that I experience at my shack. I've been working my station portable to get away from the racket.
<p>
During the week I came across something that is likely to change that.
<p>
You've no doubt heard about diversity reception. You can use two different antennas, do some fancy phase switching and make the noise go away. Now I should clarify, at least briefly what that looks like. Imagine throwing a stone into a lake, it makes waves. If you throw two stones into the lake at the same time, the waves get bigger, but if you were to time it just right, you could throw in one stone, then the next. If you timed it just so the first stone would make a wave top whilst the other stone made a wave trough, the two would cancel each other out.
<p>
You can do the same with light, shine a torch onto a piece of cardboard with two slits cut into it. Behind the cardboard you'll see light and dark patches where the frequencies line up and cancel each other out.
<p>
Light and radio waves are part of the same spectrum, so you can do the same with radio waves. You could use this technique to cancel out, or rather filter, local noise.
<p>
So far I've not said anything particular worthy of ah-ha, but stick around.
<p>
There are devices made that you can use to create the equivalent of two slits, by changing inductance and capacitance within a specific circuit, you can align two signals from two antennas and make them cancel each other out. The way that works best is if one of the antennas is really good at hearing noise and the other is responsible for hearing the required station.
<p>
You can then mix the two signals, I don't have such a device, but I'm told there is an art to making this work, and out pops the station you care about.
<p>
In software defined radio or SDR, you can do this exact same thing. Only you don't need a circuit to do it, you can show the results in real-time and you can create a user interface that makes it really easy to try different things. The example I saw is PowerSDR, an open source project that allows you to control many different radios.
<p>
Picture a circle with a line that is attached to the centre of the circle and the end is attached to your mouse pointer. You can move the mouse anywhere in the circle and as you do this, you're controlling two parameters, the phasing angle and the gain. The gain is the length of the line, the angle is the direction in which the line is pointed.
<p>
While you're moving your mouse about, the signals from both antennas are mixed together according to the position of the mouse at the time.
<p>
The end result is a completely interactive direct feedback loop where you can see and hear the effect of the mouse location. You can move it around very simply, and immediately, continuously see the result.
<p>
The outcome of all this is that you can bring your noise floor down by 30dB or more, and hear stations that were completely inaudible within the racket.
<p>
I'd heard it being described, but seeing it in action was a show stopping moment for me and right there and then I knew that the landscape in radio has changed forever.
<p>
I'm Onno VK6FLAB
<p>
This and other episodes of Foundations of Amateur Radio can be heard via podcast or download at podcasts.itmaze.com.au.
Listen:
We should stop requiring electronics to be amateurs.
Foundations of Amateur Radio
<p>
On a regular basis I receive emails from fellow amateurs and shortwave listeners who provide feedback and ideas about this weekly segment of Amateur Radio. It's a joy to read how they feel that my little contribution encourages them to continue in the hobby, or come back to the hobby, or to build something, or to do something, to participate, to experiment.
<p>
Yesterday I received an email from an amateur who came up with an idea that's worth sharing. The idea was pretty simple. Encourage every new entrant into our hobby to build a crystal radio. I know that this might sound like a trivial thing, even silly, but for me it makes complete sense.
<p>
Imagine that, building a receiver and understanding how it actually works. I know I've never actually done that and I suspect I'm not alone.
<p>
So, here's a thing. Next time you're looking for a project to do, for a thing to make, for some soldering practice, try making a crystal radio. There's opportunity to make it work for CW and SSB - think of it as an upgrade - and from an electronics perspective, this can be as complex or simple as you like.
<p>
Dovetail that with the notion of harmonics, how resonant circuits work and you're well on the way to making your first transceiver.
<p>
So, the real takeaway from this idea, not only the idea you can build a crystal radio, but that there are electronics project to be found that enhance your understanding of how radio works and are easy to build.
<p>
Now I should hasten to add, that I'm not advocating that we all become electronics experts. I know this isn't going to sit well with everyone, but let me say it again. I'm not advocating that we all become electronics experts. I know that the Standard and Advanced licenses in Australia require a fair bit of electronics, but I have to say that I think this is unhelpful.
<p>
It's taken me a long time to get to this point, so before you sharpen your pitchfork and heat up the tar and feathers, hear me out.
<p>
In Computing, which is a topic I know a lot about, having been intimate with it for nearly 45 years, there's a similar analogy. The notion that you need to know about memory, registers, about CPU clock cycles and a stack, accumulator and all manner of esoteric detail. I know all of this because 45 years ago, that defined what computing consists of. It stands me in good stead today, it makes it possible for me to conceptualise a super computer with little effort, but it's not required for someone coming into the field, learning to program and make the tools useful. It helps, but it's not required. We abstract things more and more in computing and we do the same in amateur radio.
<p>
If you think back, a spark-gap transmitter, valve based radios, transistor based radios, integrated circuit based radios and now software defined radios went through the same progression. Today an amateur doesn't learn how to build a spark-gap transmitter, though if you did, it would help your understanding of high-voltage electronics, harmonics and all manner of flow on. It's not required. A similar thing is true for building a valve based radio and over time the same will be true for transistors, integrated circuits and software.
<p>
You might think of this as a dumbing down, and to be fair, I thought the same thing for many years.
<p>
In reality, it's not dumbing down at all, it's focusing on what's important, on what makes progress, on what grows a field.
<p>
There will be always room for people who understand the difference between an NPN and a PNP transistor, but it's not required to be an amateur, even if today's amateur education system still requires it.
<p>
So what I'm saying is that, you should build a circuit, build a radio, go on to build a transceiver. You should understand what goes on under the hood because it helps you understand the implications of things when you make changes. Just like a racing car driver has no understanding of the chemistry of the fuel that is put in his car, there should be no need for you to be forced to do electronics, but it can be loads of fun and you might surprise yourself and learn something.
<p>
I'm going back to my Morse, another one of those skills which is immensely helpful, but no longer required.
<p>
I'm Onno VK6FLAB
Listen:
Picking better language to talk about our hobby ...
Foundations of Amateur Radio
<p>
Today I started doing some research on Baluns. It was prompted by a message from a fellow amateur who asked about how they work and what they do and what the difference was between a 1:1, a 1:4 and a 1:9 balun.
<p>
While doing that, I thought I'd look up what the definition was of a balun. It says right here on Google - so it must be true - that it's a type of electrical transformer used to connect an unbalanced circuit to a balanced one. I clicked on the link that said "Translations, word origin and more definitions", which showed me a history of the use of the word balun and I was hooked. The explanation of a balun will have to wait for another day.
<p>
I started looking at the use of the word going back to the 1800's, based on Google's Ngram Viewer. Looks like it was used a bit between 1800 and 1910, but steadily declining in use, until it started picking up in popularity around 1930. Today the word balun is more popular than the phrase "radio amateur", but less popular than either "amateur radio" or "ham radio".
<p>
Radio Amateur hit its peak in 1950 and Amateur Radio in 1990, when electronics also hit its peak. Ham radio hit its peak around 2000.
<p>
All of these terms pale into insignificance when compared with either the word Software or Hardware. Hardware being about 200 times more popular than any of the radio terms, but software being 700 times more popular.
<p>
So, what does this have to do with us, more specifically, what does this mean for you?
<p>
Well, if you want this amazing hobby to relate to the people around you, there might be a benefit to use language that is increasing in popularity, while still related to us, it might pull us along with the tide.
<p>
So, "Software Defined Radio" is on the rise, SDR likely means something else in 1985 when it hits peak popularity, but use is increasing.
<p>
Interestingly, Icom makes more noise in literature than Yeasu, by about 9 times. The ARRL makes more noise than the RSGB and WIA put together and balanced is 8 times more popular than unbalanced, though I won't vouch for that relating only to amateur radio.
<p>
Transistors hit their peak in 1967, capacitors did so a decade earlier, resistors even earlier in 1952.
<p>
I think this means that we need to spend some time investigating the language we use to communicate about our hobby and use it wisely to increase awareness about the things we think are amazing.
<p>
GPS is a term on the rise, antenna is pretty stable since 1965, emergency response is on the increase, communication is at an all-time-high, steadily increasing from 1900 on-wards.
<p>
Radio is staying pretty stable, but hit its peak in 1950. Television is on the decline and the Internet is more popular than either.
<p>
So, pick some words, look at the Google Ngram Viewer [https://books.google.com/ngrams] and learn some things about the words you might use to communicate about this wonderful hobby.
<p>
Can you guess, what's more popular, a dipole, a vertical or a Yagi?
<p>
I'm Onno VK6FLAB
Listen:
Radios are not quite appliances ...
Foundations of Amateur Radio
<p>
Today we have a world where radios are more and more like appliances. We can buy them at a store, ship them to our location, open the box, plug in the radio to an antenna and start operating.
<p>
I said, "like" an appliance, because a transceiver is not like a toaster in all aspects and it's those little gaps between the toaster as an appliance and a transceiver as an appliance that I want to highlight.
<p>
I was with a farmer recently who had a CB radio in his troopie, or if you're not familiar with that, a Toyota Land Cruiser, this one had 400.000km on the clock and was just getting run in. According to the farmer, the CB had never worked right. He joked that it was often easier to yell across the paddock than to use the radio. On a farm there are lots of things happening, during harvesting, heavy equipment is moving everywhere and communications are vital.
<p>
I was with a friend and the first thing that we noticed about this CB is that it was a UHF CB, that is, it was using 70cm, or 470-odd MHz. The antenna however was a HF CB antenna, 27 MHz. As a radio amateur you know that this is never going to work well. In fact it's amazing that there was any contact using this particular CB at all.
<p>
Another thing we noticed was that the connector between the radio and the antenna was loose, so it's entirely possible that the actual communication was happening around the connector on the back of the radio, rather than the antenna on the bull-bar.
<p>
You might be listening to this and shaking your head. If you're uncharitable, you might even scoff at those silly CB'ers. I think that's both unhelpful and wrong.
<p>
Precisely this is the difference between a toaster as an appliance and a transceiver as an appliance. It means that any radio training, any license at all, even a foundation call, is sufficient to learn enough to be able to diagnose such issues.
<p>
You might think that this means that I think CB'ers are stupid. Far from it. I think this means that radios are not appliances and that there is ample opportunity for the skills we take for granted as amateurs to propagate through the community.
<p>
If you're a CB'er yourself and you're not a radio amateur. Perhaps you might consider spending a weekend and getting your introduction to Amateur Radio. You are likely to learn lots of things you've never heard or understood, or more likely have been told incorrectly.
<p>
If learning how to use your transceiver, be it CB, HF club or otherwise, is important to you, have a look at Amateur Radio. I think it's important.
<p>
I'm Onno VK6FLAB
Listen:
Fieldstrength and Chickens
Foundations of Amateur Radio
<p>
Yesterday during dinner I heard an interesting story. Apparently there was a farmer who had a chicken coop that he kept warm at night by using a 240 Volt light bulb hooked up to the chicken wire surrounding his chickens. The farmer's property was in the vicinity of a local AM broadcast transmitter. They only found him because the people in the shadow of the chicken coop had bad reception.
<p>
I'm sitting at the dining table, listening to this tale and wondering, could it be true? My gut feeling was no, but surrounded by food and friends it was hard to put my finger on precisely where this doesn't add up.
<p>
A little digging revealed that the transmitter in question was the local ABC 6WF transmitter at Hamersley.
<p>
So, what do we know about this transmitter?
<p>
First of all, it's a 50 kW AM transmitter. I must confess, I have operated this station. Imagine that, 50 kW AM, with an introductory Foundation License.
<p>
Anyway, back to the 6WF transmitter. It's located on a block of land, roughly 500 meters wide, 1000 meters long. Thanks to the ACMA we have a map that shows a contour line where the field strength of this transmitter is 1 Volt per meter. That means that there is 1 Volt difference between two points a meter apart. This contour varies in distance from the antenna from 2.1 km to 1.8 km. So in a sort-of-circle around this transmitter there is a circle of points at which you can step 1 m further away and measure a field strength decrease of 1 Volt.
<p>
We also know that electric fields decrease by the inverse square of the distance, or said in another way, if you double the distance, you decrease the field strength by 4, if you increase distance by 3, you decrease strength by 9.
<p>
Of course, the opposite is also true.
<p>
If you halve the distance, from 2 km to 1 km, you increase the field strength to 4 V/m. If you have it again to 500 m, the field strength becomes 16 V/m.
<p>
To power a 240 V lamp, we'd need to get within 100 meters or so of the transmitter. Of course, the block is 500 m wide, the closest you can get without going onto the property is about 250 m, where the field strength is about 64 V/m.
<p>
So, unless the farmer had a chicken coop on the transmission site itself, this is unlikely to have happened.
<p>
Before you ask, how can an f-call operate a 50 kW AM transmitter, on 720 kHz, easy, get invited to talk about Amateur Radio with Gillian O'Shaughnessy on ABC breakfast radio. Did you know, her grand-dad was an amateur?
<p>
Anyway, if you know the farmer in question, or if you're sure it's happened, I'd love to hear about it.
<p>
I'm Onno VK6FLAB
Listen:
Change one thing at a time ...
Foundations of Amateur Radio
<p>
Whenever I go out to play radio, which is whenever I actually want to operate, I try new things. For example I've experimented with different clocks, to keep track of what time I made a contact, I've experimented with different ways of logging, with different locations, different antennas, with different bands, times of day, methods of calling CQ, methods of making a contact with a DX station, different methods of looking at propagation, different distances from interference.
<p>
As I said, every time I try something else different.
<p>
One thing I do, that might not seem obvious. I try to only change one thing. The reason I do that, is so I have a better understanding on what the change actually did. Of course this isn't entirely possible, you often cannot park in exactly the same spot, at the same time with the same propagation, but if you go out often enough, things start coming together.
<p>
So, for a clock, I use a $20 digital watch that has two time-zones. I set it to show local and UTC at the same time. For logging I use a spiral notepad. I write the date on a new page, the location, the radio, the antenna, the maidenhead locator and anything new I'm trialling.
<p>
When I listen up and down the band, I'll write down each callsign I hear, their frequency and a signal report. If I manage to make contact, which as a QRP station can be a rewarding challenge, I'll add the time, their signal report and some other information they share, like their name and location. I'll also add two exclamation marks in the margin, so I know that I need to log this contact in my logging software.
<p>
I tried using my phone, but logging software is not that good, a computer runs out of battery before you make your first contact, or just goes to sleep when you get a signal report and nothing beats looking at your wrist for seeing what time it is right now.
<p>
Antenna wise, I'm still fooling around with my mono-band verticals, it's been over a year now and while frustrating, I'm still learning about what they do and don't do. I ask most amateurs I come across about their opinion and have been given lots of great and some dud information along the way.
<p>
All in all, most of my activity is about learning. Every now and then I manage a DX contact and that's very rewarding.
<p>
Meanwhile, the hunt for Morse continues.
<p>
I'm Onno VK6FLAB
Listen:
How to get started in a contest
Foundations of Amateur Radio
<p>
There are times when you'll find yourself being encouraged to participate in a contest. You might receive an email, a Facebook encouragement, or even hear an item on the local news about a contest.
<p>
Where do you start if that's what you're interested in?
<p>
Well, first things first. You need to find out when this contest is exactly. The reason this is important is because you might go though all the preparation, only to find yourself sitting at a family BBQ listening to your favourite family member sharing the story about the dog and the lake, rather than being in the contest.
<p>
Once you've determined that you are in fact able to participate in the contest, put it in your diary. This seems obvious, but I can guarantee you that there will come a day when you're happily sitting in the sun having lunch when that sinking feeling appears and you realise that the contest you were going to play in started 8 hours ago.
<p>
Now that you've got the basics out of the way, what's next?
<p>
Find the contest website, most contests have one, in fact I can't think of one that doesn't, and look at what the aims and objectives of the contest are. Download a copy of the rules and see if there are things that exclude you from operating. The contest might be on bands you're not allowed on, or modes you're not licensed for, so make sure that you're actually allowed to participate.
<p>
Then read the rules of the contest for understanding. Most contests define who is allowed to contact whom at what time, on what frequency and how often. The rules will outline how points are calculated and how the log needs to be submitted. Other things you'll find are the deadline for log submission, the exclusions, power requirements, bonus points for low power operation, things like operating more than one radio, or having more than one operator.
<p>
Terms you'll come across are SO2R, or Single Operator Two Radios. Or Multi-Multi which means Multiple Operators with Multiple Radios, or Multi-Single, meaning Multiple Operators, One Radio and all manner of special classes as defined by the contest manager.
<p>
Previously I've talked about getting logging software together, setting up your station and testing it, but those things all need to be covered off. Make sure your computer doesn't need a Windows Update in the middle of the contest, get enough sleep before the festivities and plan for some recovery time after the contest.
<p>
This of course doesn't cover all of what you need, but it's a really good start.
<p>
Get on air and make some noise.
<p>
I'm Onno VK6FLAB
Listen:
Tools in my shack
Foundations of Amateur Radio
<p>
Today I was looking around my shack and noticed that I have lots of different amateur radio tools that go beyond the simple bits and pieces that I started with, namely a radio, battery, power supply, coax and antenna.
<p>
While I have no illusion that my gear is complete, or even representative of all of the stuff that you might need or come across, I think that it's worth while to mention a few bits and pieces that you may not have considered.
<p>
I think the first thing I got that wasn't part of the basic kit, was a dummy load. It's only a little one, rated at 50 Watts or so, but seeing that I'm only using 5, that's more than enough. I use it to check things like VOX sensitivity, that is, I want to set-up a way to talk into my radio without having to push a button - for when I'm doing a contest, and I don't actually want to transmit any signal while testing, so I plug in the dummy load and test with that. I also use it to plug into the end of a piece of coax that I'm testing. I can tell you, it's helped me find some dodgy coax over the years.
<p>
I have a range of adaptors, from PL259, SO239, N-type, SMA, BNC, male-to-male, male-to-female, female-to-female, all different permutations. They're all in one box and I have that with me whenever I go portable, it's saved my bacon more times than I can remember.
<p>
I have a multi-meter, the most often used part of it is the continuity beep. You can set it to beep if there is a short, which is great for testing power leads, coax shorts and the like.
<p>
I splurged and purchased an antenna analyser. It's helping me understand the errors of my ways while building antennas, though I confess that on more than one occasion it added to the confusion.
<p>
I have a coax cutter, a pair of high quality pliers, though one of my so called friends left it in the rain one day, so they're less quality than they were, an Anderson Powerpole crimper, a gas soldering iron - so you can solder in the field, a third-hand, since holding something while soldering is an excellent way to get a scar to impress your friends. On my workbench I have a lighted magnifying glass, since the older I get the harder it is to focus on small things. I have a bag of clip-on torroids which I use in places where operating surprises me with bonus RF interference.
<p>
I also have stuff like cable-ties, electrical tape, self-amalgamating tape and a fair bit of rope.
<p>
You'll notice that I don't have an SWR meter, I figured that the one in my radio and the antenna analyser combined were enough.
<p>
I'm sure there are other things that I take for granted, but the items I've outlined are in regular use.
<p>
I'm Onno VK6FLAB
Listen:
Wet string and 10 Watts
Foundations of Amateur Radio
<p>
Today I had the pleasure of talking to a group of freshly minted Amateurs. It's a semi-regular occurrence where I visit a local club that offers training to obtain an Amateur License. I should mention that you'll find clubs like this all over the place and there are often opportunities to do remote examinations if you're too far from an assessor. This however isn't about becoming an Amateur, that's something that I'll leave entirely up to you, even if I think that being an Amateur is a wonderful thing.
<p>
One of the things I like about this hobby is that it's different things to different people. There is a huge variety of aspects to this pursuit of Amateur Radio and as I've said in the past, it's really a thousand hobbies rolled into one.
<p>
In Australia there are three so-called classes of license, think of it as a moped licence, a car license and a truck license. If you want to drive a truck you need that one, but if you're on a moped, there's no need to spend your efforts on learning to double-de-clutch a Ranger gearbox - something I can assure you from personal experience is hard to master, but fun to get right.
<p>
The three licenses in Australia, Foundation, Standard and Advanced each have different privileges, access to different but overlapping aspects of the hobby. One privilege within the class of license that I hold, the Foundation or F-call, is that I'm limited to using 10 Watts.
<p>
I've spoken about this restriction many times, in fact, the very first time I shared my opinion about this hobby in this forum was exactly about those pesky 10 Watts and what is possible with them.
<p>
Back to the freshly minted Amateurs.
<p>
It occurred to me that while I was explaining the amazing width and breadth of our hobby, that the 10 Watts, while completely arbitrary, and often lambasted for being so, is actually a blessing in disguise.
<p>
When you get on air, or if you already have the privilege to do so, you'll learn or already know that making contacts with a wet piece of string is pretty hard, nigh on impossible with 10 Watts.
<p>
One solution is to add more power. A better, more elegant solution, is to get a better antenna.
<p>
So, the blessing in disguise that 10 Watts represents is really all about forcing a Foundation Licensee to spend considerable effort in their antenna system. Something which we might all agree on is a good thing, if only to clear the air of alligators, big mouth, no ears.
<p>
I'll take the risk of repeating myself. It's not how much power, but what you do with it that matters.
<p>
I'm Onno VK6FLAB
Listen:
Propagation and reality
Foundations of Amateur Radio
<p>
A recurring topic of conversation is propagation. There is learned discussion about sun-spots, A and K indices, forecasts, ionospheric probing, not to mention half-baked guess work from less scientific perspectives.
<p>
It's been my experience that all these tools are wonderful, but none of them beat turning on your radio and having a listen, or better still putting out a call.
<p>
So when do you listen and where do you listen?
<p>
The trivial response would be everywhere, all the time, but none of us has enough time for that.
<p>
In general, 20m, 14 MHz works most of the time. At night, frequencies lower than 20m, that is 40m, 7 MHz and 80m 3.5 MHz work better. During the day, higher frequencies, 15m, 21 MHz and 10m, 28 MHz work better.
<p>
Of course this is not a hard and fast rule. As I said previously, there is no such thing as a perfect antenna, in fact we can prove that it cannot actually exist. Similarly, there is no such thing as perfect propagation.
<p>
We tend to think of propagation in terms of layers in the ionosphere, the D, E and F layers. We might think of them as specific, distinct things, but the reality is that they're more like clouds.
<p>
Clouds are not uniform in cover, sometimes fluffy, other times dense thunderclouds and an infinite variety in between. Coverage is variable and forecasting is a real challenge. And that's for something we can see.
<p>
The ionosphere is no different. It's not uniform, it's not predictable and forecasting is hard.
<p>
Back to the clouds for a moment; you might have a forecast for rain, but it's perfectly dry where you are. Similarly, you might have a forecast of poor propagation, but it's perfectly fine where you are.
<p>
So, best tip is to use the forecasts you have access to, but stick your head out of the window to see if it's raining right now. If that was too obscure, turn on your radio and make some noise, even if the sunspot count is rubbish and the Ionospheric Prediction Service tells you that nothing is going to work.
<p>
I'm Onno VK6FLAB
Listen:
Getting started with portable operation
Foundations of Amateur Radio
<p>
Today I'm operating portable, in fact I'm operating portable every day. Though I'd have to confess, some days more than others.
<p>
I have to do this by necessity. There is lots of RF noise at home, so I'm forced to physically move away from the interference and set up elsewhere.
<p>
You can do this as simply or as complex as you like. I've done it with a bag that contained my radio, a battery and a wire antenna that I strung between two trees.
<p>
I've also gone portable with my car, camping gear, a trailer full of radio gear, a wind up mast and a rotatable dipole with a generator to provide power.
<p>
And everything in between.
<p>
My point is that for every circumstance there is a different set of tools that will solve your problem.
<p>
Several amateurs I've spoken to are quite unsure about this portable adventure and are not really geared up for such shenanigans even if they're interested to get out and about.
<p>
So what is involved with going portable?
<p>
The essence of any station is the antenna. If you know where you're going to operate and why, you can figure out what kind and how much of an antenna you need to bring. Likely a mast and rotator are not part of the deal, but I have set up a yagi on mast in a park for a contest.
<p>
If you don't know where you're going to be, you need to come up with a solution that is more flexible. Either a self supporting vertical with something like a squid pole or a wire antenna that you can throw into a tree.
<p>
The next challenge is power. Are you going to operate for a little while or are you going to set up for 48 hours to participate in a contest. Are you going to be using low power, 5 watts, or are you in a position where you can give an amplifier a workout?
<p>
Batteries, generators, your car or a solar panel, all of these can power your radio in different situations.
<p>
Are you planning to make a few contacts, or are you expecting a huge pileup to get your blood pumping? Logging for either requires a different solution.
<p>
You should always, always consider the weather when you're operating portable. Sun, wind, rain, storm, hot and cold all have different implications for you personally and the wear and tear of your equipment. So prepare yourself.
<p>
Just like when you started your shack, you had to figure out what goes where and how will I use it?
<p>
Portable operation is no different.
<p>
A tip for new players, less is more. You have to carry all this stuff, so expect to make compromises. You won't be able to take everything in your shack, unless you already built it in the back of your vehicle, in which case I'd like an invite to come and visit.
<p>
I'm Onno VK6FLAB
Listen:
Antenna Calculators
Foundations of Amateur Radio
<p>
Recently I was asked about finding the best antenna calculator. It's a tool that helps you determine what the length of an antenna should be for a particular frequency.
<p>
Picture a dipole antenna, two wires, end to end, strung out horizontally, joined in the middle by a feed point. A dipole is most effective if its total length is half of the wavelength of the frequency it's intended for.
<p>
To calculate what that is, you divide the speed of light by the frequency. So, for argument sake, the wavelength for 28.5 MHz is roughly 10 m, which makes sense, since 28.5 MHz is in the 10 m band.
<p>
If you use your favourite search engine to find a dipole calculator, you'll find many different ones. If you try a few, you'll find that the answers that each calculator gives is slightly different. For a half-wave dipole on 28.5 MHz, you'll find that there is a half meter variation among the calculated answers.
<p>
If you do this for a dipole for 3.5 MHz, you'll find the variation is just over 4 m between the shortest calculated dipole and the longest one.
<p>
That's a 5% variation across a calculated response. That's strange, since the calculation should be the same across all different calculators.
<p>
So what's going on?
<p>
Let's start with the wave length. If you use the speed of light as 300.000 km per second, then a frequency of 28.5 MHz is 10.526 m, but if you use the actual speed of light, there's a 7mm difference.
<p>
Right, simple, so there should be two types of answers, those that use 300.000 km per second and those that use the actual speed.
<p>
Unfortunately, no.
<p>
You could use "majority rules" and pick the calculated answer that turns up most often, but science isn't a democracy. It's either correct or it ain't and you have no way of knowing which is which.
<p>
What you're actually witnessing when you see all these answers with the overall 5% spread is different approximations of the answer. Calculator is a word that implies precision and accuracy, but what's actually happening is that each calculator uses their own fudge factor to get closer to the starting point. It's all in an attempt to get to an actual answer quicker, since hoisting an antenna, measuring, lowering it, trimming it, hoisting it again and so-on, is not fun with a 10m antenna, let alone an 80m antenna.
<p>
Some of the fudge is related to how high the antenna is off the ground, the thickness of the wire used, if the wire has insulation on it and how thick that insulation is, what the soil type is and what angle it's actually hanging at and how far it's from other things.
<p>
What this really means is that you need to experiment. When you buy wire, buy long, cut in little bits, measure lots and try it. A calculator will get you in the ball-park, but you already know the nominal length for a dipole as it is, it's right there, in the band name.
<p>
So, just because you've found a fancy calculator online, doesn't make it right for your circumstance.
<p>
One tip, plot all the antenna length results from the various calculators and see what the curve looks like, you'll see a wonderful distribution curve that just begs to be used.
<p>
I'm Onno VK6FLAB
Listen:
Use it or Lose it ... make a contact today!
Foundations of Amateur Radio
<p>
In your travels around the sun it's likely you've heard the phrase: "Use it or lose it."
<p>
Within the ranks of our hobby, that refers to making noise on air and using the bands we've been allocated.
<p>
It's easy to sit in your shack - in what ever form that might take - turn on your radio and scan up and down the bands to see what's going on. If something interesting catches your fancy, you might even plug your microphone or key in, and actually call the other station.
<p>
Unfortunately, that's not using the bands, that's sitting on the side and listening. Not that there is anything wrong with that, but it's no way to ensure that the bands and privileges we enjoy today are going to be here tomorrow.
<p>
Over the past few years I've come across several ideas to change that. I've seen blogs and posts from individuals who attempt to make a contact every day, in what ever form they prefer. Some don't distinguish between local or DX contacts, portable or QRP, whatever takes their fancy.
<p>
In New Zealand there's the ZL2AL Memorial Activity Marathon. You get recognition for making 4 or more contacts on a specific number of days during the year. Some amateurs are working on a single contact per day, others are attempting a QRP QSO every day.
<p>
Imagine if all the amateurs in the world made one contact every week. In Australia alone that would generate 2000 extra contacts every day.
<p>
You can limit your activity to making contacts when it suits, or during a contest, or on the way to work on the local repeater, or you can spread your wings and make contacts more often than that.
<p>
I know for a while - until my antenna circumstances changed - I was making at least one contact a day. I kept that up for nearly a year. I'm still getting the QSL cards coming in the mail.
<p>
So, don't wait for permission to get on-air. Don't wait for "just the right conditions", turn on your radio, plug in your microphone and make a contact. Why not do it right now?
<p>
I'm Onno VK6FLAB
Listen:
Propagation predictions and operating your radio
Foundations of Amateur Radio
<p>
Today propagation is what it is, yesterday it was different and tomorrow it will be different again. It's one of the fundamental aspects of amateur radio.
<p>
We talk about propagation on air, like we do the weather. Rain, sun, snow or storm, there's always something. Of course most of those weather events have no impact on radio. A rain drop isn't going to make a great deal of difference to a HF signal, other than potentially making the operator wet, or creating a short-circuit in an unexpected way.
<p>
Propagation on the other hand has little or no effect in day-to-day life, other than your GPS, mobile phone or other electronic device. In radio however, propagation makes the difference between only hearing your neighbours and speaking to another station on the other side of the globe.
<p>
In the past I've mentioned that if you skip a stone across a lake, you get a good idea about how radio waves bounce off the ionosphere and in doing so, make it possible to hear and be heard beyond the line of sight of your antenna.
<p>
A stone is a fixed object and water has a pretty uniform density, so you get mostly predictable results. The ionosphere is not uniform and radio waves are not fixed, so the result is anything but predictable.
<p>
That said, a great number of people are working on providing propagation prediction tools in an attempt to provide us with somewhat more of a reliable outcome. Once you step into this area, you'll come across the A and K indices, the Solar Flux and Geomagnetic and Solar Flare numbers.
<p>
You'll find websites like solarham.com, bandconditions.com, spaceweather.tv and many others. Sometimes they'll even agree with each other - which is interesting in itself, since the source of actual data is pretty limited. We have the Ionospheric Prediction Service or IPS in Australia, in the US there's the National Oceanic and Atmospheric Administration, or NOAA.
<p>
All this is to attempt to quantify what the sun is doing and how this affects the ionosphere and in turn our experience as radio operators.
<p>
If you know anything about predicting the weather, that is, what is the temperature going to be today and is it going to rain, you'll understand that predicting solar activity and its impact on us is a less than perfect experience. In 1959 we managed to snap the first images of the far side of the Moon, it took until 2011 for us to do the same with the sun.
<p>
Many of our predictions are really observations and imperfect ones at that, coming from the two STEREO spacecraft, one orbiting the sun ahead of the earth, the other behind the earth, combined they manage to cover the back of the sun.
<p>
In the end, the predictions on carrying an umbrella or not are like predicting whether to operate or not. It's a prediction. Nothing beats turning on your radio and having a go.
<p>
I'm Onno VK6FLAB
Listen:
Every Antenna is a Compromise!
Foundations of Amateur Radio
<p>
Recently I read a comment a fellow amateur made about an antenna. He said: "Of course, that antenna is a compromise..."
<p>
Let me say that again: "That antenna is a compromise ..."
<p>
It was the funniest thing I'd seen all week and the person making the statement wasn't even trying to be funny.
<p>
Unless you're looking at the Sun from a distance, or checking out the propagation associated with the Big Bang, All Antennas are a compromise. We can prove that an isotropic antenna, one that is a theoretical point source of radio waves, cannot actually exist, so that basically means that you cannot have it all, ever.
<p>
Once you've got your head around the notion that no such thing as a perfect antenna actually exists, or can exist, it makes sense that amateurs around the world spend so much time discussing and trialling antennas.
<p>
As you get involved in Amateur Radio, you'll soon realise that the number of variables to construct an antenna is large. The more you learn, the more variables you unearth. Initially, you'll learn that the length of the radiator will determine the resonant frequency, then you'll learn that the thickness affects this, then whether or not there is insulation, what material it's made from, how high it's off the ground, what soil type there is, what's nearby, how it's fed, where it's fed, if it's stranded or solid, not to mention shape, orientation, frequency and other variables you'll unearth along the discovery process.
<p>
The take-away should be that playing with antennas, while not immediately satisfying, is a fundamental part of this hobby. It's the final link in the chain and the single largest influence on the effectiveness of our station.
<p>
In all this, I've just looked at the physics of the antenna, but other variables also come into play. The amount of actual space you have available, the depth of your wallet, the availability of materials, the feedback from your neighbours or your local council, your family and their acceptance of your crazy pursuit. Patience and propagation also take a large chunk of the pie.
<p>
Is there the ultimate antenna? Yup. It's an isotropic antenna and it cannot exist. Everything else is up for grabs. So what ever works for you is good. Compare your efforts with your fellow amateurs and ask questions. Duplicate other efforts, trial stuff, make noise, get on air and see what happens.
<p>
A popular metaphor, that an infinite number of monkeys, banging on an infinite number of typewriters, left to their own devices, sooner or later will reproduce the works of William Shakespeare.
<p>
It's like that with amateur radio. We just evolved to play with antennas, rather than typewriters.
<p>
I'm Onno VK6FLAB
Listen:
Phonetic Alphabets
Foundations of Amateur Radio
<p>
Today we have a standard for our on-air phonetic alphabet - technically it's called a spelling alphabet, but I digress.
<p>
As you should be aware if you're a licensed Amateur, we use the so-called standard phonetic alphabet. It's used and defined by several organisations, including the International Telecommunications Union, the International Civil Aviation Organisation and NATO.
<p>
It should come as no surprise that each of those organisations defines their own alphabet. It just so happens that today each of these definitions is the same, but that hasn't always been the case.
<p>
In the United Kingdom, Alpha went through Apples, Ack, Ace, Able an Affirm.
<p>
In the United States, Alpha has been Able, Affirmative, Afirm, Able, Alfa.
<p>
In Amateur Radio we've heard America, Amsterdam and even Australia.
<p>
All that for just the letter that we spell as Alpha.
<p>
If that's not enough, try on Adams, Adam, Anatole, Anton, Ancona, Antonio, Anna, Aarne, Adana, Aveiro, Amor, Ana and Avala.
<p>
No wonder we have a few different spellings that we hear on air when we're busy spelling our callsign to the other station.
<p>
Where does that leave you?
<p>
Well, the ACMA specifies in their amateur operating procedures the International Phonetic Alphabet and it is recommended for use by amateur station licensees.
<p>
Note that it's recommended, not mandated.
<p>
My best advice is to learn and love the standard phonetic alphabet. It's been almost standard since 1956. That's not to say you won't hear me call Victor King Six Florida London America Boston on occasion, when I'm trying to talk to some station that hasn't a clue that I have a legitimate callsign with a four letter suffix and they need to be sure that I know that it's real.
<p>
The recommended procedure when dealing with a Pirate is to go silent. You won't believe how many stations went quiet whilst I was working my latest contest. Those four letters do cause some grief, but I understand, it was only introduced recently, as close as 2005, so it's understandable that not everyone has heard of an Australian Foundation call, let alone get their head around the standard phonetic alphabet.
<p>
I'm Onno Vice Kilogramme, Soxisix, Frank Loves Amsterdam Beer
Listen:
What to say in a contest...
Foundations of Amateur Radio
<p>
Today I want to talk about things to say and do in a contest. Before I begin, I must point out that there are many views on this and depending on your aim for the contest, what I'm going to talk about will be different.
<p>
First of all, a contest is an Amateur Radio activity that starts and stops at a particular time. Often this time is expressed as UTC, or Universal Time. Since there are several official time-zones and more unofficial time-zones here in VK alone, you'll need to check your own location to determine what the actual local time is, but for my money, I have a watch that is set to UTC and during a contest I put it on my wrist.
<p>
Apart from the rules for each contest, often described in mind-numbing detail with particular exceptions for different issues, often grown over time, there is a basic aim to get on air, make contact with other stations and exchange a salient piece of information. This information of course varies with the contest, but the most common exchange is a serial number.
<p>
What that means is that your first contact is 001, your second 002 and so-on.
<p>
I mention the double zero, since they are often expected and leaving them out is a source of confusion for the other station. Especially if their first language isn't English.
<p>
So, you give out a signal report, followed by the serial number which often will be something like 59001, 59002 and so on.
<p>
The very first thing people say about a contest is that signal reports are bogus. The reason they're bogus, always 5/9, is because it reduces the time it takes to say them, and more importantly, to log them. Most contesting software doesn't require you to enter the signal report and you need to spend extra effort to change them, often much more than just typing in the correct digits. So, despite your misgivings, if you're in a contest and you're talking to another contester and you're playing to win, then 5/9 is the signal report.
<p>
If you make many contacts you'll learn that there is a rhythm to making a contest contact. The more rhythmic you can make it, the more likely you'll succeed in getting through the contact quicker.
<p>
And that really is the point, less words, more contacts, saving your voice, less misunderstanding, better contest result.
<p>
This is not the conduct you'd do on a rainy Tuesday afternoon when you're chewing the fat, or on air also known as rag-chewing, this is specifically during a contest or pile-up.
<p>
In the local contests it's fine to say "Hi", use the words "My number to you is", but in the rest of the world these are just not helping. During a contest there is no discussion about your radio, your antenna, your dog or what you'd like to buy when you win LOTTO, it's about the quickest, most accurate contact you can make.
<p>
Let's imagine I'm searching and pouncing; that means I'm moving around the band looking for contacts. Let's imagine that K1DG is running; which means they're on a single frequency calling CQ Contest. The bare bones of a contest contact between K1DG and VK6FLAB during an SSB contest contact would be like this:
<p>
K1DG contest
VK6FLAB
VK6FLAB 59667
QSL 59667 59001
QSL 59001
K1DG contest
<p>
Now in that exchange I've said a grand total of 18 words. K1DG has said 23. The whole thing is 41 words, no more, no less. Of course, callsign length increases or decreases that count.
<p>
Some things to observe.
<p>
I never say their callsign. There is an assumption that if you're calling someone who is running you'll spend a few moments listening for their callsign, either before or after the contact, no need to tell them what it is, they already know it and it's 4 words extra, plus the pause between the two callsigns, it breaks the rhythm of the contact.
<p>
K1DG when he's running a pile-up is not going to call CQ, but not saying his callsign at all is worse than not saying CQ. There are people who are tuning up and down the band like I was, who want to know who the station is because they may or may not want to work the station. And the opposite is also true, the station might want to work you. So if you're the running station, say your callsign at the end of every contact.
<p>
Note that the rhythm continues. In the example, after confirming my number, K1DG has already called "contest" and is ready for the next contact.
<p>
Note that there is no discussion about anything other than the exchange. It's over before it began and in a contest or a pile-up, that's a really good thing. Less transmission means less noise, means faster contacts, means more stations getting an exchange, everybody wins.
<p>
Finally, this is about a contest or pile-up exchange. It isn't about a day-to-day contact, but it pays to know and practice it.
<p>
I'm Onno VK6FLAB
Listen:
1000 hobbies under one roof
Foundations of Amateur Radio
<p>
The hobby we call Amateur Radio is hard to explain to anyone outside. I was recently asked about what it was about the experience that had me hooked. I talked about Summits on the Air, SOTA, Islands on the Air, IOTA, World Wide Flora and Fauna, WWFF and satellite communications. DX hunting and competitions, but I never quite managed to capture what it all really means.
<p>
Since then I came across a really wonderful explanation about what it is that we have here.
<p>
Said simply, Amateur Radio is a thousand hobbies in one place, each with their own community, their own skills, their own gear, pursuits and club-songs.
<p>
For some it's the pursuit of making a contact using low power and Morse-code, for the next it's building the key to make that happen, the next person wants to build the radio, the amplifier, the twin-feed, the mast, go camping, etc. etc.
<p>
The characterisation of 1000 hobbies in one place under the umbrella also helps in other ways. It highlights that we're all different, with experiences that are both shared and unique. All coming together under the single, almost trivial moniker of: "I am a radio amateur."
<p>
The take-away from this is of course that you can do inside our hobby what interests you. Find people with the same outlook, or people who are smarter than you, or people who push you, or make you laugh, or make fun of you. All these things are within our hobby.
<p>
Your job is simple. Find your own place among us.
<p>
I'm Onno VK6FLAB
Listen:
Names in Amateur Radio
Foundations of Amateur Radio
<p>
The origins of names of things in Amateur Radio has a long and internet riddled history, with hear-say and false memories added.
<p>
The humble BNC connector was patented in 1951. BNC doesn't stand for Baby N-Connector, Bayonet N-connector, British Naval Connector, Berry Nice Connector, Berkeley Neucleonics Corporation or any such name. Apparently, it's named after it's inventors Paul Neill and Carl Concelman, the Bayonet Neill-Concelman connector. They went on to invent the Threaded Neill-Concelman connector, the TNC. A sub-miniature version of these connectors came in three types, A, B and C, called SMA, SMB and SMC.
<p>
Also, the N-type connector was invented by the very same Paul Neill at Bell Labs, and the C connector came from Carl.
<p>
The Yagi antenna, was invented in 1926 by Shintaro Uda in collaboration with Hidetsugu Yagi, both of Tohoku Imperial University in Japan. It's actually called an Yagi-Uda antenna. Yagi described the antenna in English in 1928 and his name became associated with the antenna.
<p>
The PL-259 and SO-239 connectors are not so clear-cut. The PL for plug and SO for socket seems to be agreed on. There are several explanations on the numbers, but the most persistent one seems to be that it was a US army part number. They're also referred to as UHF connectors and if you know that they were invented in the 1930s, you'll understand that UHF frequencies started at 30MHz and "above", which in practical terms meant 300MHz. An interesting thing to note is that a standard banana plug mates properly with an SO239, so you can just plug your long-wire straight into the socket.
<p>
Of course we have the Volt, the Ohm, the Ampere and the Farad, named after Italian physicist Alessandro Volta, German physicist Georg Simon Ohm, French physicist and mathematician André-Marie Ampère and English physicist Michael Faraday.
<p>
Everything is named after something. Sometimes we even remember what that was and where it came from.
<p>
What things have you learned about names in Amateur Radio?
<p>
I'm Onno VK6FLAB
Listen:
Do your thing and find friends to play with
Foundations of Amateur Radio
<p>
Today in Amateur Radio is no different from yesterday, last year, last decade or longer. The hobby today is filled with people who are here to have fun, learn stuff and experiment. This hasn't changed since our hobby came into being.
<p>
You can argue that the hobby has seen a great many changes. We have seen spark-gap transmitters, valves, transistors, miniaturisation, chips and now software defined radios. The experimental nature of our pursuit has not changed.
<p>
We still spend time looking for cool stuff to do and people to do it with.
<p>
And that's the single point I'd like to make.
<p>
Finding people "to do it with".
<p>
If you're a new amateur you might look to a club or your fellow classmates to combine your efforts. This can be a great way to forge life-long friendships and it's a sure fire way to find exposure to other ideas and activities.
<p>
There might come a time when you find yourself at a loss what to do next, or who to do it with. You might lament that the group you're hanging out with are not doing fun stuff anymore, or that activities never quite happen or any number of observations that make it less fun to be part of amateur radio.
<p>
I've now been here for a little while and I've noticed that some of my fellow amateurs have fallen by the way-side. Of course family and changing interests will account for some of that, but often it's a lack of something to do that makes people fade away.
<p>
There is nothing stopping you from organising your own event. You can plan a camp-out, or an antenna testing day, or a DX activity, a contest, an activation, some software hacking, or hardware building, soldering training, learning how to log, how to do a QSO, or any number of other things.
<p>
If you tell the community about it, you're likely to be surprised by some other amateur who was just thinking to do the same thing.
<p>
So, don't wait for someone else to do your fun activity. If you focus on doing things that you enjoy, you might find a few like-minded friends who will participate.
<p>
I'm keen to hear your ideas and activities, so drop me a line.
<p>
I'm Onno VK6FLAB
Listen:
Radio Amateur - the local lunatic
Foundations of Amateur Radio
<p>
There are things that surprise me about this amazing hobby of Amateur Radio every day.
<p>
One thing that is not a surprise is that some part of the general public thinks that I'm crazy, a lunatic, or worse, someone or something to be feared.
<p>
Picture this.
<p>
My car is parked in a car-park, next to some bush-land. Behind the car is a 12m fibre-glass squid-pole with a delta-loop hanging off it. The car-doors are open, it's a warm day, and I'm sitting in the driver's seat with a good friend coaching from the passenger side.
<p>
I'm calling CQ and trying to figure out if this antenna works.
<p>
Cue, Isobelle, she's the local ranger for the park we're in. She pulls up in her truck and comes out with "So, what's going on here then?"
<p>
We explain that we're radio amateurs and that we're testing an antenna. She tells us that someone has seen us, phoned it into the ranger and she's been tasked to come out and check.
<p>
We'd been set-up for all of 15 minutes.
<p>
Two days later, I'm in my local park, 2 minutes walk from my home, trying to see if the delta-loop will reduce some of the RF noise I get at home. I've brought along a fishing rod, some guy wires, walked around the park, found a suitable tree, unpacked my stuff, cast a sinker across the tree, hoisted up the delta-loop, secured it to a nearby fence and strapped the feed point to the tree with some webbing.
<p>
I'm sitting on the ground with my radio, having a fine chat with a fellow amateur when two likely lads walk up in ranger uniforms. I tell my fellow amateur that I've got to go, as I have two visitors. We finish up and I ask, "Hello, how can I help you?"
<p>
One ranger tells me that they have had a report from a neighbour who told them that there was this lunatic putting ropes in trees and doing weird stuff. He goes on to tell me that he's quite disappointed to see the actuality of a radio amateur setting up an antenna.
<p>
Seems our ranger was in the emergency services in a prior life and has some experience with HF wire antennae.
<p>
They have a look around to make sure that it's not unsafe and that I've not damaged any trees and finish off with wishing me a great day.
<p>
I learned two things from this. Expect to be noticed and think about how the public might interact with what you're doing. Also, be mindful of public safety, ensure that your setup isn't a health hazard to someone.
<p>
So, those are my lunatic amateur stories, what stories do you have to tell? Drop me a line and let me know.
<p>
I'm Onno VK6FLAB
Listen:
Delta Loop for Portable Operation
Foundations of Amateur Radio
<p>
Today I learned something new. A good antenna makes a big difference and you can hear it.
<p>
Of late, I've been using the antennas on the boot of my car and have for some time all but abandoned my 12m spider-beam squid pole. As you might recall, the very first antenna I ever built was a quasi-random length vertical with 16 radials. Each of the 17 wires is about 12.5 meters long, so there is a lot of wire, wound onto a garden hose reel for transport, lots of effort in setting up, lining up and stuff to do before I can actually get on air. In a HF quiet area it works pretty well but it's too big for most back yards; it takes up a circle of 25m diameter and needs either guy wires or a car at the base.
<p>
I went back to the drawing board. Using my trusty SG237 antenna coupler, I found a design online for a delta-loop. It's 120 foot or just over 36.5 meters of wire, setup in a triangle with the SGC coupler at the middle of the base. Yes, I know, the take-off angle isn't optimal, but oh my, what a difference in signal strength. Of course, from a setting up perspective, strap the squid pole to a vertical structure of some sort, roll out the wire, stick it to the top of the pole, erect the pole, click the antenna coupler in place and you're good to go. Call it 5 minutes.
<p>
Perhaps an analogy that will help is that the difference between the HF antenna in my car and the delta-loop suspended from the 12m pole is like cleaning your glasses, you can see perfectly well through them, but when you clean them, you can see more than you thought was there.
<p>
For my portable contest and QRP operation I'm going to have a look-see at a set of delta-loops, still suspended from my squid-pole, but this time cut to resonant length with no tuner at the base at all - and I can feed it at the bottom corner where it makes for a better take-off angle.
<p>
Before I forget, a take-off angle is like the angle at which you skip a stone across a lake. If you do it too steep, you get bloop, rather than a skipping stone; the better the angle, the more skips. The same is true for HF radio signals. Make the angle too high and you get bloop, make it low and you can hear stuff on the other side of the planet.
<p>
The experimentation with antennas continues, and I'm beginning to learn, it will for the rest of my life.
<p>
I'm Onno VK6FLAB
Listen:
Hunting for the perfect SWR.
Foundations of Amateur Radio
<p>
There is a persistent perception among a small part of the amateur community that you need to build, buy or use antennas with a perfect 1:1 SWR to get the best results. Sometimes a contest erupts with who can get the lowest SWR.
<p>
Without getting technical, since that could take hours and you have better things to do. A 50 Ohm dummy load has a perfect SWR of 1:1 and you should already know that a proper dummy load doesn't radiate, so while it has a perfect SWR it's not a perfect antenna.
<p>
If your SWR meter reads 1.5:1, you're losing 3% of your signal, at 2:1 it's 11%, so just because the SWR is 2, doesn't mean you've got a dud antenna.
<p>
Now I should point out that this can be a particularly dense topic if you get into the finer detail and if you do a search for "Understanding SWR by Example", you'll come across a delightful and very detailed document written by Darrin K5DVW and published in QST magazine that goes into pictures, graphs and explanations and also discusses ladder line.
<p>
So, you can now stop hunting for the perfect 1:1 SWR and learn what your SWR meter is telling you.
<p>
I'm Onno VK6FLAB
Listen:
Tuning a dipole, bring your friends...
Foundations of Amateur Radio
<p>
This week I spent several hours in a park with a mast, guy wires, some coax, an antenna analyser, copper wire, a balun, cable ties and a pair of pliers, not to mention a tape measure, a calculator and several experienced amateurs.
<p>
We set out to create a linked dipole antenna for a portable activation that we're working on.
<p>
If you're unfamiliar with the concept of a linked dipole, it's simple. Imagine a dipole for 10m. It's about 5m long with a connection to the feed in the middle. At each end of the dipole is a connector of some sort - in our case, just some bare wire while we were building the contraption - and then some method of joining a piece of wire, in such a way that you can either opt to have the bits electrically connected, or just physically.
<p>
If you repeat this, then you end up with a normal dipole that's made up of segments that you can either connect or not. This means that when a segment is connected, the dipole becomes resonant on a lower frequency, since the electrical length increases, and if you disconnect it, it becomes resonant on a higher frequency.
<p>
The purpose of this contraption is to have a single antenna that you can simply lift up in the middle and use. To change bands, you lower the thing, then you either disconnect or connect a segment, and then you raise it again.
<p>
The internet is full of calculators that will give you the length of a dipole for a given frequency. You'll find some that account for the thickness of the wire, the thickness of any insulation and the angle at which the dipole is hanging from the centre and the height above ground.
<p>
Unfortunately my experience thus far is that none of these actually give you the real length, just the theoretical one. The actual length could be longer or shorter, so this means that for any given calculator, you need to cut the wire long and then trim as required. While you're doing this, the length of the antenna changes, the angle at which your antenna hangs changes and the height of the antenna above ground also changes.
<p>
If that's not enough, the soil on which your antenna is being built will change the characteristics of the antenna as well.
<p>
Most of this wasn't a surprise to me and as soon as you start playing with this, you'll observe the very same phenomenon.
<p>
What took me by surprise is that the method of tuning, cut, measure, cut, measure, cut, measure, cut, that I'd been using with much frustration is still the very same method if you're an experienced amateur.
<p>
The only difference that I could discern in the shared activity was that it came with jokes, laughter, arguments and assistance, which when you're doing something as frustrating as tuning a wire dipole, is a great benefit.
<p>
So, thank you to my friends for starting this caper. And if you're off on a dipole building party, bring some friends. It won't make it any easier, but it will be more rewarding.
<p>
I'm Onno VK6FLAB
Listen:
7Ps of Amateur Radio - be prepared
Foundations of Amateur Radio
<p>
Amateur Radio is as much about having fun as it is about learning. Sometimes they go hand-in-hand, sometimes not so much.
<p>
The 7Ps of Amateur Radio are as valid today as they were 100 years ago, Proper Planning and Preparation Prevents Piss Poor Performance.
<p>
Amateur Radio Planning can take many forms, but the basics include creating a permanent checklist. The notion of creating one every time means that you forget every time what you learned last time, so if you create a permanent one and then revise it from time-to-time, you'll be able to incorporate lessons learned, like "bring the radio face-plate control cable", and "bring the quarter inch jack adaptor", so you don't end up repeating the same lesson over and over.
<p>
Test your gear at home. Not just turn it on, but set up the mast, check that you have guy wires and anchors. Check that you have enough coax to connect your antenna to your radio, spare batteries, etc. One trick I learned recently is to have a red and green label or elastic band. Attach the appropriate colour to your batteries, so you can instantly see if the battery you're lifting up is charged or not.
<p>
Look at maps, bring instructions to get to places, look at Google Earth and remember that power lines might not show up on a satellite map, but they're sure going to annoy you when you get on air. Street view is handy to check out power-lines.
<p>
Try different antennas. Verticals are easy to setup, but sometimes depending on your location they can be noisy. Dipoles need two supports, but an inverted V only needs one. Wire antennas can be simple to make and cheap to get bits for and repair, but they're not like the yagi you left at home.
<p>
A really helpful comment I read from Julie VK3FOWL and Joe VK3YSP is that you shouldn't be embarrassed by your hobby. Be seen, be visible, talk to people. You'll be amazed at the amount of interest you get, people are curious, they'll sticky-beak whenever they can.
<p>
Amateur Radio is not the only thing you can do when you're out and about. Go for walks, go hiking, fishing or drink beer around the campfire, whatever floats your boat.
<p>
Just like you can see stars at night in the bush, you can hear radio when you're away from interference. You'll hear stuff you never heard before and likely you'll get hooked into either astronomy or radio in the bush, or both.
<p>
There is much more to discuss about planning, but the basic premise is that it pays to think through the activity, the process of packing, driving, setting up, operating, living on-site, packing up and driving back. Think about food, safety, emergencies, fuel, and remember, Amateur Radio is not worth dying over, this is a hobby. Laugh, have fun, be merry.
<p>
Yes, in case you're wondering, the 7Ps don't come from Amateur Radio, but just like the US Marine Corps Antenna Handbook, search for "r3403c", we can learn lots from them about both antennas and planning.
<p>
I'm Onno VK6FLAB
Listen:
Cabrillo and ADIF file formats
Foundations of Amateur Radio
<p>
Cabrillo and ADIF are likely two terms you've heard if you've done anything with logging or contesting. So what are they, how do they work and why does it matter?
<p>
Let's start with Cabrillo. It's a file format used for submitting an electronic log to a contest manager. It was developed by Trey N5KO in 1999 for the ARRL. It's up to version 3.0, but the intent is that the older v2 files are still readable by todays programmes.
<p>
The aim of the Cabrillo format is to provide some meta information, like the contest name, the person who did the contest, what club they're part of, where they live, what category, etc.
<p>
After that, each contact is shown as a single line with a fixed format that shows the frequency, the mode, time-stamp, exchange and other pertinent details.
<p>
Significantly it does not contain any point information, because the intent is that the contest manager imports each log and their software calculates the actual score, dealing with the rules as defined by the contest, duplicates, multipliers etc.
<p>
The format for all of this is precisely defined and all the fields for a contact are required. The only other comment about Cabrillo is that it was developed to allow both humans and computers to read it easily.
<p>
At first glance, the ADIF format is all but the same. It deals with amateur radio stuff, contacts and the like.
<p>
But at second glance, ADIF, or Amateur Data Interchange Format is really not the same.
<p>
For starters, if you open up an ADIF file in a text editor you'll immediately notice that it's all but unreadable by a human. If you know what you're looking at you have a good chance to glean meaning, but at the first look it will appear as gobble-de-gook.
<p>
The ADIF file format is intended to be a way of exchanging any amateur information, such as awards multipliers, packet spot data, contest rules and it is intended to be expandable to include and incorporate any new kind of information as our hobby evolves.
<p>
There are countless ADIF fields, things like the reporting a short wave listener report, or an encryption key, or the grid square of the station, or the propagation mode, or any number of other values.
<p>
So, if you think of Cabrillo as the bare-bones of a contest contact log and ADIF as all the information you ever wanted to log and hadn't thought of logging, you'll have the right idea.
<p>
I should point out that both file formats are text. That means that if you open them up in a text editor you can look at them.
<p>
Word of warning for the unwary, you can really break an ADIF file by editing it in a text editor.
<p>
If you want to exchange amateur radio information with another amateur, use ADIF. If you want to submit a contest log, use Cabrillo.
<p>
I'm Onno VK6FLAB
Listen:
Amateur Radio FAQ's
Foundations of Amateur Radio
<p>
There are questions that happen, over and over again. In computing they're called FAQ's, or Frequently Asked Questions.
<p>
Here are some that happen in Amateur Radio.
<p>
What radio should I buy?
<p>
It depends on your budget. Where are you going to be using this radio, at home, in the car, in a park or on a mountain? Will you have power where you are, will you be using HF, or will you be using VHF, UHF and above? Ask other amateurs around you, use their radios and have a play.
<p>
<p>
What is the best antenna?
<p>
The one that works. You can buy, build or borrow. Try out several ones, trade off size, space, cost, functionality and simplicity. It can be as simple as a single piece of wire, or as complex as a remote controlled and adjustable multi-band antenna.
<p>
<p>
When should I be trying to make a contact, or what is the best frequency to be on?
<p>
The one that works. If you're tuning up and down the band and you hear nothing, and you've checked that the squelch isn't closed and your antenna is connected, change bands and have a look elsewhere. You might think that there are specific times for specific bands, but that just isn't true. There are too many variables to make a hard and fast rule. You'll get pleasant surprises at sun-rise and sun-set. Look up the grey-line.
<p>
<p>
How much power do I need?
<p>
Just enough to make the contact. Sometimes that's 5 Watts or less, sometimes 100 Watts isn't enough. Conditions vary greatly and every time you turn on your radio is a new adventure.
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<p>
Can I use my radio in the car legally?
<p>
Yes. Your hand microphone is permitted in a vehicle, it's not classed as a mobile phone and you cannot be booked for using it, BUT, you can still be charged for dangerous driving, so don't be an idiot on the road. If in doubt, don't. Life is not worth a DX entity, even if you've been trying for 38 years.
<p>
<p>
Why should I care about contesting, it's not my style.
<p>
It exposes you to working on-air in adverse situations. There is lots of activity, lots of interference and making contacts can be hard if you've never done it. If you learn how to operate in a contest, then when the time comes and an emergency of some-sort occurs, you'll be well practised in the art of making a contact when the going is tough. Think of a contest as a perfect excuse to learn how to use your radio.
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<p>
Why do I keep hearing Sugar and Washington, instead of Sierra and Whisky?
<p>
Because the Americans think that the NATO alphabet doesn't apply to them. You will find that some stations just cannot hear "Sierra", but respond immediately to "Sugar" which may tempt you to use that by default. Opinion is divided on the best practice, but the ACMA specifies that you use the NATO alphabet and they are the people who grant you your license.
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<p>
Should I always use phonetics in my callsign?
<p>
Yes. There are some who think that it's a waste of air-time on VHF and UHF, but it depends entirely on the conditions. If you're operating with a station that you know well, then you might be able to go with the non-phonetic version, but if in doubt, use phonetics. On an international conversation, it's good practice to use phonetics, since not everyone around you will be listening to a 5 and 9 signal.
<p>
<p>
What's the best wire to use for an antenna?
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There are only two types of wire, cheap wire and free wire. When in doubt, go with the free wire.
<p>
<p>
Should I upgrade my license?
<p>
That depends entirely on why you're in Amateur Radio. If you're here to have a yarn and your current license suits you, then leave well enough alone. If you want a structured environment to learn more stuff, do an upgrade. If you want more privileges, more bands, more modes, more power, do an upgrade. If you're happy as you are, read, talk and learn. One day you might want to upgrade. Don't ever upgrade because someone tells you that you must. This is your hobby. If you stay within your license conditions, then carry on and have fun.
<p>
<p>
If you have other questions, or if you didn't like my answers, drop me a line.
<p>
I'm Onno VK6FLAB
Listen:
What radio should I purchase?
Foundations of Amateur Radio
<p>
A regular question that I hear from amateurs, both new and experienced ones, is "What radio should I purchase?". It's a simple question that doesn't have a simple answer.
<p>
The obvious variables, budget, size, frequency and modes are one side of the coin, and when you start looking, you'll learn that there is a lot of information on the subject. You'll learn that you can get amateur radios from $15 to $20,000 and everything in between. To be clear, I'm just talking about the radio, not the power supply, the amplifier, microphone, computer, antenna, interfaces, Morse key and the like.
<p>
Unless you won LOTTO yesterday, and not even then, you should probably not buy a $20,000 radio first up, but if you do, make sure you give me a call and I'll help you test it.
<p>
The question that often happens is, should I buy a Yaesu or Icom, which is like asking, should I buy a Mac or PC, or a Holden or a Ford. As you know, there are many different options and the same is true for your radio.
<p>
The reality is that unless you have specialised measuring equipment, most modern radios are pretty similar. That's not to say that they are the same, far from it, it's just that you are unlikely to come across a situation where you'd actually notice, since the variables that make up our hobby are so vast, propagation, antennas, local environment and the like, that any slight differences in radio performance are likely to be completely masked by other factors.
<p>
Again, I'm not saying that there are no differences. If you have a shack where you have 10 radios side-by-side, all connected to the same antenna, you'll be able to notice differences, sometimes they'll even be significant, but overall, in day-to-day operation, other variables beyond the simple metric of "performance" are more important.
<p>
The budget you have is a big factor when you get your radio, and don't spend more than 50% of your total budget on the radio, since you'll need a whole lot of other stuff that simply isn't in the box. Antennas, power supplies, coax, headphones, microphones, etc. are just the basics.
<p>
When you've narrowed it down to a couple of radios, go and visit some shacks and see them in operation. Try to work like you would work on one of those radios. If you're a contester, try a contest on a friend's radio, if you like working portable, go out with your friend and see how the radio performs.
<p>
There's nothing wrong with picking the radio that your friend has, since it will help you learn more about your own gear.
<p>
Since my first purchase I've learned lots about radios. I have no regrets that my first radio was a Yeasu 857d, but I picked it because it suited me. I can tell you that I don't think that my next radio will be the same. There is lots that I like, and some things I don't.
<p>
Even the most experienced ham asks their friends for their opinion. My current one is to recommend an open source software defined radio, but I've not actually used one yet and I already know I dislike the software that it ships with, so there's that.
<p>
I'm Onno VK6FLAB.
Listen:
Different soil types ...
Foundations of Amateur Radio
<p>
Recently I had the opportunity to operate mobile in 30 different locations within a 24 hour period. I'd done some preparatory work, in the way of looking closely at maps and plotting my expected route to know where I was and how far it was to the next location.
<p>
One of the things I noticed while operating was that my signal reports varied greatly. I also noticed that the local noise floor was quite variable, power lines don't realy show up on a map and I can tell you that they are not your friend.
<p>
One aspect of operation that took me a little by surprise, though it probably shouldn't have, was that different soil types made a big difference. I know that when I'm playing with antenna modeling software you have the opportunity to specify the soil type, but that doesn't really translate into anything that you can personally experience.
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The way I mainly noticed the effect is that for any given frequency, my ATU was unable to tune for some soil types, wet was good, rock wasn't.
<p>
This was the first time that I'd actually experienced that in such a way that I managed to notice what was going on, rather than a theoretical experiment, this was a practical exercise and well worth the effort of moving around.
<p>
Next time you go out portable, or mobile, have a look at what is happening around you, one of the actual variables is the ground beneath your antenna.
<p>
I'm Onno VK6FLAB
Listen:
Welcome
Foundations of Amateur Radio
<p>
This podcast started life in 2011 when I was asked to record a story I shared during the production of the weekly amateur radio news in Western Australia.
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I'd been a licensed radio amateur, or ham, for a few months and found myself surrounded by people who perceived the basic Australian foundation amateur licence wasn't worth anything.
<p>
What use is an F-call? is my response to that sentiment. It's produced weekly.
<p>
In 2015 after long deliberation it was renamed to Foundations of Amateur Radio so people outside Australia might also enjoy the experience.
<p>
Although most of the items stand alone, I'd recommend that you start at the beginning in 2011 and listen in sequence.
<p>
Enjoy.
<p>
I'm Onno VK6FLAB
Listen:
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